--- tool: Crawlinx SEO audit source: https://crawlinx.com domain: lifesciencetextbook.com report_url: "https://crawlinx.com/audit/lifesciencetextbook.com" crawl_id: 20260724T174601-3256c238 health_score: 68 generated_at: 2026-08-26T04:05:09Z total_pages: 50 html_pages: 50 indexable_pages: 50 errors: 0 warnings: 57 notices: 338 --- # SEO audit: lifesciencetextbook.com **Health score: 68/100** — needs attention > Audited by [Crawlinx](https://crawlinx.com) — the free technical-SEO crawler. Full report: https://crawlinx.com/audit/lifesciencetextbook.com ## Overview | Metric | Value | | --- | --- | | Pages crawled | 50 | | HTML pages | 50 | | Indexable | 50 | | Non-indexable | 0 | | Orphan pages | 0 | | Broken internal links | 0 | | Avg response time | 1310 ms | | Errors / Warnings / Notices | 0 / 57 / 338 | | Status codes | 50×200 | ## Categories | Category | Score | Errors | Warnings | Notices | | --- | ---: | ---: | ---: | ---: | | Duplicate | 72 | 0 | 46 | 16 | | Meta Description | 96 | 0 | 6 | 41 | | Agent Readiness | 99 | 0 | 2 | 0 | | Headings | 99 | 0 | 1 | 9 | | Performance | 99 | 0 | 1 | 111 | | Structured Data | 99 | 0 | 1 | 48 | | Content | 100 | 0 | 0 | 55 | | Images | 100 | 0 | 0 | 2 | | Security | 100 | 0 | 0 | 50 | | Social | 100 | 0 | 0 | 6 | ## Issues ### Warnings (57) #### Control has no accessible name - Rule: `agent.control_no_name` · Category: Agent Readiness · Occurrences: 2 - [https://www.lifesciencetextbook.com/](https://www.lifesciencetextbook.com/) — 1 button/link(s) with no text or aria-label — an agent can't target them - [https://www.lifesciencetextbook.com/product-page/sample-product](https://www.lifesciencetextbook.com/product-page/sample-product) — 2 button/link(s) with no text or aria-label — an agent can't target them #### Near-duplicate page content - Rule: `duplicate.near` · Category: Duplicate · Occurrences: 35 - [https://www.lifesciencetextbook.com/about-us-1](https://www.lifesciencetextbook.com/about-us-1) — near-duplicate of 34 page(s): https://www.lifesciencetextbook.com/about-us-7, https://www.lifesciencetextbook.com/contact, https://www.lifesciencetextbook.com/about-us-18 - [https://www.lifesciencetextbook.com/about-us-10](https://www.lifesciencetextbook.com/about-us-10) — near-duplicate of 34 page(s): https://www.lifesciencetextbook.com/about-us-7, https://www.lifesciencetextbook.com/contact, https://www.lifesciencetextbook.com/about-us-18 - [https://www.lifesciencetextbook.com/about-us-11](https://www.lifesciencetextbook.com/about-us-11) — near-duplicate of 34 page(s): https://www.lifesciencetextbook.com/about-us-7, https://www.lifesciencetextbook.com/contact, https://www.lifesciencetextbook.com/about-us-18 - [https://www.lifesciencetextbook.com/about-us-12](https://www.lifesciencetextbook.com/about-us-12) — near-duplicate of 34 page(s): https://www.lifesciencetextbook.com/about-us-7, https://www.lifesciencetextbook.com/contact, https://www.lifesciencetextbook.com/about-us-18 - [https://www.lifesciencetextbook.com/about-us-13](https://www.lifesciencetextbook.com/about-us-13) — near-duplicate of 34 page(s): https://www.lifesciencetextbook.com/about-us-7, https://www.lifesciencetextbook.com/contact, https://www.lifesciencetextbook.com/about-us-18 - [https://www.lifesciencetextbook.com/about-us-14](https://www.lifesciencetextbook.com/about-us-14) — near-duplicate of 34 page(s): https://www.lifesciencetextbook.com/about-us-7, https://www.lifesciencetextbook.com/contact, https://www.lifesciencetextbook.com/about-us-18 - [https://www.lifesciencetextbook.com/about-us-15](https://www.lifesciencetextbook.com/about-us-15) — near-duplicate of 34 page(s): https://www.lifesciencetextbook.com/about-us-7, https://www.lifesciencetextbook.com/contact, https://www.lifesciencetextbook.com/about-us-18 - [https://www.lifesciencetextbook.com/about-us-16](https://www.lifesciencetextbook.com/about-us-16) — near-duplicate of 34 page(s): https://www.lifesciencetextbook.com/about-us-7, https://www.lifesciencetextbook.com/contact, https://www.lifesciencetextbook.com/about-us-18 - [https://www.lifesciencetextbook.com/about-us-18](https://www.lifesciencetextbook.com/about-us-18) — near-duplicate of 34 page(s): https://www.lifesciencetextbook.com/about-us-7, https://www.lifesciencetextbook.com/contact, https://www.lifesciencetextbook.com/about-us-13 - [https://www.lifesciencetextbook.com/about-us-19](https://www.lifesciencetextbook.com/about-us-19) — near-duplicate of 34 page(s): https://www.lifesciencetextbook.com/about-us-7, https://www.lifesciencetextbook.com/contact, https://www.lifesciencetextbook.com/about-us-18 - [https://www.lifesciencetextbook.com/about-us-2](https://www.lifesciencetextbook.com/about-us-2) — near-duplicate of 34 page(s): https://www.lifesciencetextbook.com/about-us-7, https://www.lifesciencetextbook.com/contact, https://www.lifesciencetextbook.com/about-us-18 - [https://www.lifesciencetextbook.com/about-us-21](https://www.lifesciencetextbook.com/about-us-21) — near-duplicate of 34 page(s): https://www.lifesciencetextbook.com/about-us-7, https://www.lifesciencetextbook.com/contact, https://www.lifesciencetextbook.com/about-us-18 - [https://www.lifesciencetextbook.com/about-us-22](https://www.lifesciencetextbook.com/about-us-22) — near-duplicate of 34 page(s): https://www.lifesciencetextbook.com/about-us-7, https://www.lifesciencetextbook.com/contact, https://www.lifesciencetextbook.com/about-us-18 - [https://www.lifesciencetextbook.com/about-us-23](https://www.lifesciencetextbook.com/about-us-23) — near-duplicate of 34 page(s): https://www.lifesciencetextbook.com/about-us-7, https://www.lifesciencetextbook.com/contact, https://www.lifesciencetextbook.com/about-us-18 - [https://www.lifesciencetextbook.com/about-us-3](https://www.lifesciencetextbook.com/about-us-3) — near-duplicate of 34 page(s): https://www.lifesciencetextbook.com/about-us-7, https://www.lifesciencetextbook.com/contact, https://www.lifesciencetextbook.com/about-us-18 - [https://www.lifesciencetextbook.com/about-us-4](https://www.lifesciencetextbook.com/about-us-4) — near-duplicate of 34 page(s): https://www.lifesciencetextbook.com/about-us-7, https://www.lifesciencetextbook.com/contact, https://www.lifesciencetextbook.com/about-us-18 - [https://www.lifesciencetextbook.com/about-us-5](https://www.lifesciencetextbook.com/about-us-5) — near-duplicate of 34 page(s): https://www.lifesciencetextbook.com/about-us-7, https://www.lifesciencetextbook.com/contact, https://www.lifesciencetextbook.com/about-us-18 - [https://www.lifesciencetextbook.com/about-us-6](https://www.lifesciencetextbook.com/about-us-6) — near-duplicate of 34 page(s): https://www.lifesciencetextbook.com/about-us-7, https://www.lifesciencetextbook.com/contact, https://www.lifesciencetextbook.com/about-us-18 - [https://www.lifesciencetextbook.com/about-us-7](https://www.lifesciencetextbook.com/about-us-7) — near-duplicate of 34 page(s): https://www.lifesciencetextbook.com/contact, https://www.lifesciencetextbook.com/about-us-18, https://www.lifesciencetextbook.com/about-us-13 - [https://www.lifesciencetextbook.com/about-us-8](https://www.lifesciencetextbook.com/about-us-8) — near-duplicate of 34 page(s): https://www.lifesciencetextbook.com/about-us-7, https://www.lifesciencetextbook.com/contact, https://www.lifesciencetextbook.com/about-us-18 - [https://www.lifesciencetextbook.com/about-us-9](https://www.lifesciencetextbook.com/about-us-9) — near-duplicate of 34 page(s): https://www.lifesciencetextbook.com/about-us-7, https://www.lifesciencetextbook.com/contact, https://www.lifesciencetextbook.com/about-us-18 - [https://www.lifesciencetextbook.com/blank-page](https://www.lifesciencetextbook.com/blank-page) — near-duplicate of 34 page(s): https://www.lifesciencetextbook.com/about-us-7, https://www.lifesciencetextbook.com/contact, https://www.lifesciencetextbook.com/about-us-18 - [https://www.lifesciencetextbook.com/blank-page-1](https://www.lifesciencetextbook.com/blank-page-1) — near-duplicate of 34 page(s): https://www.lifesciencetextbook.com/about-us-7, https://www.lifesciencetextbook.com/contact, https://www.lifesciencetextbook.com/about-us-18 - [https://www.lifesciencetextbook.com/blank-page-4](https://www.lifesciencetextbook.com/blank-page-4) — near-duplicate of 34 page(s): https://www.lifesciencetextbook.com/about-us-7, https://www.lifesciencetextbook.com/contact, https://www.lifesciencetextbook.com/about-us-18 - [https://www.lifesciencetextbook.com/blank-page-5](https://www.lifesciencetextbook.com/blank-page-5) — near-duplicate of 34 page(s): https://www.lifesciencetextbook.com/about-us-7, https://www.lifesciencetextbook.com/contact, https://www.lifesciencetextbook.com/about-us-18 - [https://www.lifesciencetextbook.com/contact](https://www.lifesciencetextbook.com/contact) — near-duplicate of 34 page(s): https://www.lifesciencetextbook.com/about-us-7, https://www.lifesciencetextbook.com/about-us-18, https://www.lifesciencetextbook.com/about-us-13 - [https://www.lifesciencetextbook.com/digital-teacher-s-guide](https://www.lifesciencetextbook.com/digital-teacher-s-guide) — near-duplicate of 34 page(s): https://www.lifesciencetextbook.com/about-us-7, https://www.lifesciencetextbook.com/contact, https://www.lifesciencetextbook.com/about-us-18 - [https://www.lifesciencetextbook.com/sample-lesson-1](https://www.lifesciencetextbook.com/sample-lesson-1) — near-duplicate of 34 page(s): https://www.lifesciencetextbook.com/about-us-7, https://www.lifesciencetextbook.com/contact, https://www.lifesciencetextbook.com/about-us-18 - [https://www.lifesciencetextbook.com/sample-lesson-2](https://www.lifesciencetextbook.com/sample-lesson-2) — near-duplicate of 34 page(s): https://www.lifesciencetextbook.com/about-us-7, https://www.lifesciencetextbook.com/contact, https://www.lifesciencetextbook.com/about-us-18 - [https://www.lifesciencetextbook.com/sample-lesson-3](https://www.lifesciencetextbook.com/sample-lesson-3) — near-duplicate of 34 page(s): https://www.lifesciencetextbook.com/about-us-7, https://www.lifesciencetextbook.com/contact, https://www.lifesciencetextbook.com/about-us-18 - [https://www.lifesciencetextbook.com/sample-lesson-4](https://www.lifesciencetextbook.com/sample-lesson-4) — near-duplicate of 34 page(s): https://www.lifesciencetextbook.com/about-us-7, https://www.lifesciencetextbook.com/contact, https://www.lifesciencetextbook.com/about-us-18 - [https://www.lifesciencetextbook.com/sample-lesson-5](https://www.lifesciencetextbook.com/sample-lesson-5) — near-duplicate of 34 page(s): https://www.lifesciencetextbook.com/about-us-7, https://www.lifesciencetextbook.com/contact, https://www.lifesciencetextbook.com/about-us-18 - [https://www.lifesciencetextbook.com/scientists-included-in-the-lessons](https://www.lifesciencetextbook.com/scientists-included-in-the-lessons) — near-duplicate of 34 page(s): https://www.lifesciencetextbook.com/about-us-7, https://www.lifesciencetextbook.com/contact, https://www.lifesciencetextbook.com/about-us-18 - [https://www.lifesciencetextbook.com/store-policies-1](https://www.lifesciencetextbook.com/store-policies-1) — near-duplicate of 34 page(s): https://www.lifesciencetextbook.com/about-us-7, https://www.lifesciencetextbook.com/contact, https://www.lifesciencetextbook.com/about-us-18 - [https://www.lifesciencetextbook.com/table-of-contents](https://www.lifesciencetextbook.com/table-of-contents) — near-duplicate of 34 page(s): https://www.lifesciencetextbook.com/about-us-7, https://www.lifesciencetextbook.com/contact, https://www.lifesciencetextbook.com/about-us-18 #### Duplicate across pages - Rule: `duplicate.title` · Category: Duplicate · Occurrences: 11 - [https://www.lifesciencetextbook.com/blank-page](https://www.lifesciencetextbook.com/blank-page) — title shared by 6 pages: https://www.lifesciencetextbook.com/book-s-evolution, https://www.lifesciencetextbook.com/scientists-included-in-the-lessons, https://www.lifesciencetextbook.com/materials - [https://www.lifesciencetextbook.com/blank-page-1](https://www.lifesciencetextbook.com/blank-page-1) — title shared by 6 pages: https://www.lifesciencetextbook.com/book-s-evolution, https://www.lifesciencetextbook.com/scientists-included-in-the-lessons, https://www.lifesciencetextbook.com/materials - [https://www.lifesciencetextbook.com/book-s-evolution](https://www.lifesciencetextbook.com/book-s-evolution) — title shared by 6 pages: https://www.lifesciencetextbook.com/scientists-included-in-the-lessons, https://www.lifesciencetextbook.com/materials, https://www.lifesciencetextbook.com/blank-page - [https://www.lifesciencetextbook.com/materials](https://www.lifesciencetextbook.com/materials) — title shared by 6 pages: https://www.lifesciencetextbook.com/book-s-evolution, https://www.lifesciencetextbook.com/scientists-included-in-the-lessons, https://www.lifesciencetextbook.com/blank-page - [https://www.lifesciencetextbook.com/purchase-options](https://www.lifesciencetextbook.com/purchase-options) — title shared by 3 pages: https://www.lifesciencetextbook.com/sample-lesson-3, https://www.lifesciencetextbook.com/rationale-and-strategies - [https://www.lifesciencetextbook.com/rationale-and-strategies](https://www.lifesciencetextbook.com/rationale-and-strategies) — title shared by 3 pages: https://www.lifesciencetextbook.com/sample-lesson-3, https://www.lifesciencetextbook.com/purchase-options - [https://www.lifesciencetextbook.com/sample-lesson-1](https://www.lifesciencetextbook.com/sample-lesson-1) — title shared by 2 pages: https://www.lifesciencetextbook.com/store-policies-1 - [https://www.lifesciencetextbook.com/sample-lesson-2](https://www.lifesciencetextbook.com/sample-lesson-2) — title shared by 6 pages: https://www.lifesciencetextbook.com/book-s-evolution, https://www.lifesciencetextbook.com/scientists-included-in-the-lessons, https://www.lifesciencetextbook.com/materials - [https://www.lifesciencetextbook.com/sample-lesson-3](https://www.lifesciencetextbook.com/sample-lesson-3) — title shared by 3 pages: https://www.lifesciencetextbook.com/purchase-options, https://www.lifesciencetextbook.com/rationale-and-strategies - [https://www.lifesciencetextbook.com/scientists-included-in-the-lessons](https://www.lifesciencetextbook.com/scientists-included-in-the-lessons) — title shared by 6 pages: https://www.lifesciencetextbook.com/book-s-evolution, https://www.lifesciencetextbook.com/materials, https://www.lifesciencetextbook.com/blank-page - [https://www.lifesciencetextbook.com/store-policies-1](https://www.lifesciencetextbook.com/store-policies-1) — title shared by 2 pages: https://www.lifesciencetextbook.com/sample-lesson-1 #### Missing <h1> - Rule: `h1.missing` · Category: Headings · Occurrences: 1 - [https://www.lifesciencetextbook.com/blank-page-3](https://www.lifesciencetextbook.com/blank-page-3) #### Hero/LCP image is lazy-loaded (loading=lazy delays LCP) - Rule: `images.no_lazy_lcp_candidate` · Category: Performance · Occurrences: 1 - [https://www.lifesciencetextbook.com/about-us-25](https://www.lifesciencetextbook.com/about-us-25) — the likely hero/LCP image (discoveringlifescience_front(6).jpg) has loading="lazy" — Google explicitly warns against lazy-loading the LCP image, because it delays the fetch until layout completes. Remove loading="lazy" from the first significant image and add fetchpriority="high" instead. #### Missing meta description - Rule: `meta_desc.missing` · Category: Meta Description · Occurrences: 6 - [https://www.lifesciencetextbook.com/about-us-25](https://www.lifesciencetextbook.com/about-us-25) - [https://www.lifesciencetextbook.com/blank-page](https://www.lifesciencetextbook.com/blank-page) - [https://www.lifesciencetextbook.com/blank-page-1](https://www.lifesciencetextbook.com/blank-page-1) - [https://www.lifesciencetextbook.com/blank-page-7](https://www.lifesciencetextbook.com/blank-page-7) - [https://www.lifesciencetextbook.com/blank-page-8](https://www.lifesciencetextbook.com/blank-page-8) - [https://www.lifesciencetextbook.com/store-policies-1](https://www.lifesciencetextbook.com/store-policies-1) #### Product schema missing required or recommended properties - Rule: `schema.product_incomplete` · Category: Structured Data · Occurrences: 1 - [https://www.lifesciencetextbook.com/product-page/sample-product](https://www.lifesciencetextbook.com/product-page/sample-product) — Product structured data is missing required properties (offers.price, offers.priceCurrency) — without them Google won't generate the rich result. Add each field (and validate with the Rich Results Test). It is also missing recommended properties (brand, aggregateRating, review), which enrich the result. ### Notices (338) #### Low text-to-HTML ratio - Rule: `content.low_ratio` · Category: Content · Occurrences: 50 - [https://www.lifesciencetextbook.com/](https://www.lifesciencetextbook.com/) — 0.4% - [https://www.lifesciencetextbook.com/about-us-1](https://www.lifesciencetextbook.com/about-us-1) — 0.4% - [https://www.lifesciencetextbook.com/about-us-10](https://www.lifesciencetextbook.com/about-us-10) — 0.4% - [https://www.lifesciencetextbook.com/about-us-11](https://www.lifesciencetextbook.com/about-us-11) — 0.4% - [https://www.lifesciencetextbook.com/about-us-12](https://www.lifesciencetextbook.com/about-us-12) — 0.4% - [https://www.lifesciencetextbook.com/about-us-13](https://www.lifesciencetextbook.com/about-us-13) — 0.4% - [https://www.lifesciencetextbook.com/about-us-14](https://www.lifesciencetextbook.com/about-us-14) — 0.2% - [https://www.lifesciencetextbook.com/about-us-15](https://www.lifesciencetextbook.com/about-us-15) — 0.2% - [https://www.lifesciencetextbook.com/about-us-16](https://www.lifesciencetextbook.com/about-us-16) — 0.3% - [https://www.lifesciencetextbook.com/about-us-18](https://www.lifesciencetextbook.com/about-us-18) — 0.2% - [https://www.lifesciencetextbook.com/about-us-19](https://www.lifesciencetextbook.com/about-us-19) — 0.2% - [https://www.lifesciencetextbook.com/about-us-2](https://www.lifesciencetextbook.com/about-us-2) — 0.3% - [https://www.lifesciencetextbook.com/about-us-21](https://www.lifesciencetextbook.com/about-us-21) — 0.2% - [https://www.lifesciencetextbook.com/about-us-22](https://www.lifesciencetextbook.com/about-us-22) — 0.2% - [https://www.lifesciencetextbook.com/about-us-23](https://www.lifesciencetextbook.com/about-us-23) — 0.2% - [https://www.lifesciencetextbook.com/about-us-24](https://www.lifesciencetextbook.com/about-us-24) — 0.4% - [https://www.lifesciencetextbook.com/about-us-25](https://www.lifesciencetextbook.com/about-us-25) — 0.5% - [https://www.lifesciencetextbook.com/about-us-3](https://www.lifesciencetextbook.com/about-us-3) — 0.3% - [https://www.lifesciencetextbook.com/about-us-4](https://www.lifesciencetextbook.com/about-us-4) — 0.3% - [https://www.lifesciencetextbook.com/about-us-5](https://www.lifesciencetextbook.com/about-us-5) — 0.3% - [https://www.lifesciencetextbook.com/about-us-6](https://www.lifesciencetextbook.com/about-us-6) — 0.3% - [https://www.lifesciencetextbook.com/about-us-7](https://www.lifesciencetextbook.com/about-us-7) — 0.3% - [https://www.lifesciencetextbook.com/about-us-8](https://www.lifesciencetextbook.com/about-us-8) — 0.4% - [https://www.lifesciencetextbook.com/about-us-9](https://www.lifesciencetextbook.com/about-us-9) — 0.4% - [https://www.lifesciencetextbook.com/blank-page](https://www.lifesciencetextbook.com/blank-page) — 0.2% - [https://www.lifesciencetextbook.com/blank-page-1](https://www.lifesciencetextbook.com/blank-page-1) — 0.4% - [https://www.lifesciencetextbook.com/blank-page-3](https://www.lifesciencetextbook.com/blank-page-3) — 1.0% - [https://www.lifesciencetextbook.com/blank-page-4](https://www.lifesciencetextbook.com/blank-page-4) — 0.4% - [https://www.lifesciencetextbook.com/blank-page-5](https://www.lifesciencetextbook.com/blank-page-5) — 0.4% - [https://www.lifesciencetextbook.com/blank-page-6](https://www.lifesciencetextbook.com/blank-page-6) — 0.4% - [https://www.lifesciencetextbook.com/blank-page-7](https://www.lifesciencetextbook.com/blank-page-7) — 0.6% - [https://www.lifesciencetextbook.com/blank-page-8](https://www.lifesciencetextbook.com/blank-page-8) — 0.4% - [https://www.lifesciencetextbook.com/book-s-evolution](https://www.lifesciencetextbook.com/book-s-evolution) — 1.1% - [https://www.lifesciencetextbook.com/contact](https://www.lifesciencetextbook.com/contact) — 0.3% - [https://www.lifesciencetextbook.com/digital-teacher-s-guide](https://www.lifesciencetextbook.com/digital-teacher-s-guide) — 0.3% - [https://www.lifesciencetextbook.com/format](https://www.lifesciencetextbook.com/format) — 0.3% - [https://www.lifesciencetextbook.com/index](https://www.lifesciencetextbook.com/index) — 0.3% - [https://www.lifesciencetextbook.com/materials](https://www.lifesciencetextbook.com/materials) — 0.4% - [https://www.lifesciencetextbook.com/product-page/sample-product](https://www.lifesciencetextbook.com/product-page/sample-product) — 0.2% - [https://www.lifesciencetextbook.com/purchase-options](https://www.lifesciencetextbook.com/purchase-options) — 0.9% - [https://www.lifesciencetextbook.com/rationale-and-strategies](https://www.lifesciencetextbook.com/rationale-and-strategies) — 0.5% - [https://www.lifesciencetextbook.com/sample-lesson-1](https://www.lifesciencetextbook.com/sample-lesson-1) — 0.4% - [https://www.lifesciencetextbook.com/sample-lesson-2](https://www.lifesciencetextbook.com/sample-lesson-2) — 0.3% - [https://www.lifesciencetextbook.com/sample-lesson-3](https://www.lifesciencetextbook.com/sample-lesson-3) — 0.3% - [https://www.lifesciencetextbook.com/sample-lesson-4](https://www.lifesciencetextbook.com/sample-lesson-4) — 0.3% - [https://www.lifesciencetextbook.com/sample-lesson-5](https://www.lifesciencetextbook.com/sample-lesson-5) — 0.3% - [https://www.lifesciencetextbook.com/sample-lesson-6](https://www.lifesciencetextbook.com/sample-lesson-6) — 0.3% - [https://www.lifesciencetextbook.com/scientists-included-in-the-lessons](https://www.lifesciencetextbook.com/scientists-included-in-the-lessons) — 0.2% - [https://www.lifesciencetextbook.com/store-policies-1](https://www.lifesciencetextbook.com/store-policies-1) — 0.3% - [https://www.lifesciencetextbook.com/table-of-contents](https://www.lifesciencetextbook.com/table-of-contents) — 0.3% #### Main text is hard to read (low Flesch Reading Ease) - Rule: `content.readability_poor` · Category: Content · Occurrences: 5 - [https://www.lifesciencetextbook.com/about-us-25](https://www.lifesciencetextbook.com/about-us-25) — this page reads as difficult (Flesch Reading Ease 48, below 50) — long sentences and multi-syllable words make it hard to scan. Shorten sentences and prefer plainer words to widen your audience. Density can be legitimate for expert, technical or legal content, so judge it against who the page is for. - [https://www.lifesciencetextbook.com/blank-page](https://www.lifesciencetextbook.com/blank-page) — this page reads as difficult (Flesch Reading Ease 48, below 50) — long sentences and multi-syllable words make it hard to scan. Shorten sentences and prefer plainer words to widen your audience. Density can be legitimate for expert, technical or legal content, so judge it against who the page is for. - [https://www.lifesciencetextbook.com/format](https://www.lifesciencetextbook.com/format) — this page reads as difficult (Flesch Reading Ease 41, below 50) — long sentences and multi-syllable words make it hard to scan. Shorten sentences and prefer plainer words to widen your audience. Density can be legitimate for expert, technical or legal content, so judge it against who the page is for. - [https://www.lifesciencetextbook.com/index](https://www.lifesciencetextbook.com/index) — this page reads as difficult (Flesch Reading Ease 49, below 50) — long sentences and multi-syllable words make it hard to scan. Shorten sentences and prefer plainer words to widen your audience. Density can be legitimate for expert, technical or legal content, so judge it against who the page is for. - [https://www.lifesciencetextbook.com/materials](https://www.lifesciencetextbook.com/materials) — this page reads as difficult (Flesch Reading Ease 40, below 50) — long sentences and multi-syllable words make it hard to scan. Shorten sentences and prefer plainer words to widen your audience. Density can be legitimate for expert, technical or legal content, so judge it against who the page is for. #### Duplicate meta description across pages - Rule: `duplicate.meta_desc` · Category: Duplicate · Occurrences: 16 - [https://www.lifesciencetextbook.com/about-us-1](https://www.lifesciencetextbook.com/about-us-1) — meta description shared by 2 pages: https://www.lifesciencetextbook.com/sample-lesson-6 - [https://www.lifesciencetextbook.com/about-us-11](https://www.lifesciencetextbook.com/about-us-11) — meta description shared by 2 pages: https://www.lifesciencetextbook.com/about-us-7 - [https://www.lifesciencetextbook.com/about-us-12](https://www.lifesciencetextbook.com/about-us-12) — meta description shared by 2 pages: https://www.lifesciencetextbook.com/about-us-6 - [https://www.lifesciencetextbook.com/about-us-14](https://www.lifesciencetextbook.com/about-us-14) — meta description shared by 6 pages: https://www.lifesciencetextbook.com/about-us-18, https://www.lifesciencetextbook.com/about-us-22, https://www.lifesciencetextbook.com/about-us-21 - [https://www.lifesciencetextbook.com/about-us-15](https://www.lifesciencetextbook.com/about-us-15) — meta description shared by 6 pages: https://www.lifesciencetextbook.com/about-us-18, https://www.lifesciencetextbook.com/about-us-14, https://www.lifesciencetextbook.com/about-us-22 - [https://www.lifesciencetextbook.com/about-us-16](https://www.lifesciencetextbook.com/about-us-16) — meta description shared by 6 pages: https://www.lifesciencetextbook.com/about-us-18, https://www.lifesciencetextbook.com/about-us-14, https://www.lifesciencetextbook.com/about-us-22 - [https://www.lifesciencetextbook.com/about-us-18](https://www.lifesciencetextbook.com/about-us-18) — meta description shared by 6 pages: https://www.lifesciencetextbook.com/about-us-14, https://www.lifesciencetextbook.com/about-us-22, https://www.lifesciencetextbook.com/about-us-21 - [https://www.lifesciencetextbook.com/about-us-21](https://www.lifesciencetextbook.com/about-us-21) — meta description shared by 6 pages: https://www.lifesciencetextbook.com/about-us-18, https://www.lifesciencetextbook.com/about-us-14, https://www.lifesciencetextbook.com/about-us-22 - [https://www.lifesciencetextbook.com/about-us-22](https://www.lifesciencetextbook.com/about-us-22) — meta description shared by 6 pages: https://www.lifesciencetextbook.com/about-us-18, https://www.lifesciencetextbook.com/about-us-14, https://www.lifesciencetextbook.com/about-us-21 - [https://www.lifesciencetextbook.com/about-us-5](https://www.lifesciencetextbook.com/about-us-5) — meta description shared by 2 pages: https://www.lifesciencetextbook.com/about-us-9 - [https://www.lifesciencetextbook.com/about-us-6](https://www.lifesciencetextbook.com/about-us-6) — meta description shared by 2 pages: https://www.lifesciencetextbook.com/about-us-12 - [https://www.lifesciencetextbook.com/about-us-7](https://www.lifesciencetextbook.com/about-us-7) — meta description shared by 2 pages: https://www.lifesciencetextbook.com/about-us-11 - [https://www.lifesciencetextbook.com/about-us-9](https://www.lifesciencetextbook.com/about-us-9) — meta description shared by 2 pages: https://www.lifesciencetextbook.com/about-us-5 - [https://www.lifesciencetextbook.com/blank-page-5](https://www.lifesciencetextbook.com/blank-page-5) — meta description shared by 2 pages: https://www.lifesciencetextbook.com/sample-lesson-5 - [https://www.lifesciencetextbook.com/sample-lesson-5](https://www.lifesciencetextbook.com/sample-lesson-5) — meta description shared by 2 pages: https://www.lifesciencetextbook.com/blank-page-5 - [https://www.lifesciencetextbook.com/sample-lesson-6](https://www.lifesciencetextbook.com/sample-lesson-6) — meta description shared by 2 pages: https://www.lifesciencetextbook.com/about-us-1 #### Multiple <h1> elements - Rule: `h1.multiple` · Category: Headings · Occurrences: 9 - [https://www.lifesciencetextbook.com/about-us-2](https://www.lifesciencetextbook.com/about-us-2) — 2 <h1> elements - [https://www.lifesciencetextbook.com/about-us-3](https://www.lifesciencetextbook.com/about-us-3) — 2 <h1> elements - [https://www.lifesciencetextbook.com/about-us-5](https://www.lifesciencetextbook.com/about-us-5) — 2 <h1> elements - [https://www.lifesciencetextbook.com/about-us-6](https://www.lifesciencetextbook.com/about-us-6) — 2 <h1> elements - [https://www.lifesciencetextbook.com/rationale-and-strategies](https://www.lifesciencetextbook.com/rationale-and-strategies) — 3 <h1> elements - [https://www.lifesciencetextbook.com/sample-lesson-3](https://www.lifesciencetextbook.com/sample-lesson-3) — 4 <h1> elements - [https://www.lifesciencetextbook.com/sample-lesson-4](https://www.lifesciencetextbook.com/sample-lesson-4) — 3 <h1> elements - [https://www.lifesciencetextbook.com/sample-lesson-6](https://www.lifesciencetextbook.com/sample-lesson-6) — 3 <h1> elements - [https://www.lifesciencetextbook.com/scientists-included-in-the-lessons](https://www.lifesciencetextbook.com/scientists-included-in-the-lessons) — 3 <h1> elements #### Likely hero image lacks fetchpriority=high - Rule: `images.hero_no_fetchpriority` · Category: Performance · Occurrences: 11 - [https://www.lifesciencetextbook.com/blank-page-3](https://www.lifesciencetextbook.com/blank-page-3) — the likely hero/LCP image (fdcd97_eeb9f4a4dd514c9da9902feccff449e4~mv2.jpg) has no fetchpriority="high" — adding it tells the browser to fetch the hero earlier in the waterfall, reducing Largest Contentful Paint. This is a low-severity nudge; verify the flagged image is actually your LCP element. - [https://www.lifesciencetextbook.com/blank-page-7](https://www.lifesciencetextbook.com/blank-page-7) — the likely hero/LCP image (fdcd97_274da4b229d548a09022c40b661b466b~mv2.jpg) has no fetchpriority="high" — adding it tells the browser to fetch the hero earlier in the waterfall, reducing Largest Contentful Paint. This is a low-severity nudge; verify the flagged image is actually your LCP element. - [https://www.lifesciencetextbook.com/book-s-evolution](https://www.lifesciencetextbook.com/book-s-evolution) — the likely hero/LCP image (fdcd97_0dd433a677e540a2842a1a6a35bc0d26~mv2.jpg) has no fetchpriority="high" — adding it tells the browser to fetch the hero earlier in the waterfall, reducing Largest Contentful Paint. This is a low-severity nudge; verify the flagged image is actually your LCP element. - [https://www.lifesciencetextbook.com/digital-teacher-s-guide](https://www.lifesciencetextbook.com/digital-teacher-s-guide) — the likely hero/LCP image (fdcd97_ff1ee872cb8249caa0ebc1cce01199e8~mv2.jpg) has no fetchpriority="high" — adding it tells the browser to fetch the hero earlier in the waterfall, reducing Largest Contentful Paint. This is a low-severity nudge; verify the flagged image is actually your LCP element. - [https://www.lifesciencetextbook.com/format](https://www.lifesciencetextbook.com/format) — the likely hero/LCP image (fdcd97_b49d16b6978e4c6dbb935304b4c81ce0~mv2.jpg) has no fetchpriority="high" — adding it tells the browser to fetch the hero earlier in the waterfall, reducing Largest Contentful Paint. This is a low-severity nudge; verify the flagged image is actually your LCP element. - [https://www.lifesciencetextbook.com/index](https://www.lifesciencetextbook.com/index) — the likely hero/LCP image (fdcd97_3428522b6b824b28a97ad767cabbbda8~mv2.png) has no fetchpriority="high" — adding it tells the browser to fetch the hero earlier in the waterfall, reducing Largest Contentful Paint. This is a low-severity nudge; verify the flagged image is actually your LCP element. - [https://www.lifesciencetextbook.com/materials](https://www.lifesciencetextbook.com/materials) — the likely hero/LCP image (fdcd97_e34f1c1334614217bcf5c026c9c9fd03~mv2.jpg) has no fetchpriority="high" — adding it tells the browser to fetch the hero earlier in the waterfall, reducing Largest Contentful Paint. This is a low-severity nudge; verify the flagged image is actually your LCP element. - [https://www.lifesciencetextbook.com/product-page/sample-product](https://www.lifesciencetextbook.com/product-page/sample-product) — the likely hero/LCP image (3c76e2_bf235c38610f4d2a905db71095b351cf~mv2_jpg_v1_fit_w_1000%2ch_1000%2cq_90_file.jpg) has no fetchpriority="high" — adding it tells the browser to fetch the hero earlier in the waterfall, reducing Largest Contentful Paint. This is a low-severity nudge; verify the flagged image is actually your LCP element. - [https://www.lifesciencetextbook.com/rationale-and-strategies](https://www.lifesciencetextbook.com/rationale-and-strategies) — the likely hero/LCP image (fdcd97_1d1a5d5c30c34076928de5e7724f817f~mv2.jpg) has no fetchpriority="high" — adding it tells the browser to fetch the hero earlier in the waterfall, reducing Largest Contentful Paint. This is a low-severity nudge; verify the flagged image is actually your LCP element. - [https://www.lifesciencetextbook.com/scientists-included-in-the-lessons](https://www.lifesciencetextbook.com/scientists-included-in-the-lessons) — the likely hero/LCP image (fdcd97_86d9ca38e2e44b1799237e2e5aa5c38b~mv2.jpg) has no fetchpriority="high" — adding it tells the browser to fetch the hero earlier in the waterfall, reducing Largest Contentful Paint. This is a low-severity nudge; verify the flagged image is actually your LCP element. - [https://www.lifesciencetextbook.com/table-of-contents](https://www.lifesciencetextbook.com/table-of-contents) — the likely hero/LCP image (fdcd97_ff1ee872cb8249caa0ebc1cce01199e8~mv2.jpg) has no fetchpriority="high" — adding it tells the browser to fetch the hero earlier in the waterfall, reducing Largest Contentful Paint. This is a low-severity nudge; verify the flagged image is actually your LCP element. #### Images without width/height (layout shift / CLS) - Rule: `images.missing_dimensions` · Category: Images · Occurrences: 2 - [https://www.lifesciencetextbook.com/blank-page-3](https://www.lifesciencetextbook.com/blank-page-3) — 4 of 5 images without width/height - [https://www.lifesciencetextbook.com/product-page/sample-product](https://www.lifesciencetextbook.com/product-page/sample-product) — 2 of 8 images without width/height #### Meta description too long - Rule: `meta_desc.too_long` · Category: Meta Description · Occurrences: 41 - [https://www.lifesciencetextbook.com/](https://www.lifesciencetextbook.com/) — 299 chars - [https://www.lifesciencetextbook.com/about-us-1](https://www.lifesciencetextbook.com/about-us-1) — 205 chars - [https://www.lifesciencetextbook.com/about-us-10](https://www.lifesciencetextbook.com/about-us-10) — 286 chars - [https://www.lifesciencetextbook.com/about-us-11](https://www.lifesciencetextbook.com/about-us-11) — 226 chars - [https://www.lifesciencetextbook.com/about-us-12](https://www.lifesciencetextbook.com/about-us-12) — 261 chars - [https://www.lifesciencetextbook.com/about-us-13](https://www.lifesciencetextbook.com/about-us-13) — 307 chars - [https://www.lifesciencetextbook.com/about-us-14](https://www.lifesciencetextbook.com/about-us-14) — 191 chars - [https://www.lifesciencetextbook.com/about-us-15](https://www.lifesciencetextbook.com/about-us-15) — 191 chars - [https://www.lifesciencetextbook.com/about-us-16](https://www.lifesciencetextbook.com/about-us-16) — 191 chars - [https://www.lifesciencetextbook.com/about-us-18](https://www.lifesciencetextbook.com/about-us-18) — 191 chars - [https://www.lifesciencetextbook.com/about-us-19](https://www.lifesciencetextbook.com/about-us-19) — 192 chars - [https://www.lifesciencetextbook.com/about-us-2](https://www.lifesciencetextbook.com/about-us-2) — 320 chars - [https://www.lifesciencetextbook.com/about-us-21](https://www.lifesciencetextbook.com/about-us-21) — 191 chars - [https://www.lifesciencetextbook.com/about-us-22](https://www.lifesciencetextbook.com/about-us-22) — 191 chars - [https://www.lifesciencetextbook.com/about-us-23](https://www.lifesciencetextbook.com/about-us-23) — 190 chars - [https://www.lifesciencetextbook.com/about-us-24](https://www.lifesciencetextbook.com/about-us-24) — 288 chars - [https://www.lifesciencetextbook.com/about-us-3](https://www.lifesciencetextbook.com/about-us-3) — 287 chars - [https://www.lifesciencetextbook.com/about-us-4](https://www.lifesciencetextbook.com/about-us-4) — 312 chars - [https://www.lifesciencetextbook.com/about-us-5](https://www.lifesciencetextbook.com/about-us-5) — 304 chars - [https://www.lifesciencetextbook.com/about-us-6](https://www.lifesciencetextbook.com/about-us-6) — 261 chars - [https://www.lifesciencetextbook.com/about-us-7](https://www.lifesciencetextbook.com/about-us-7) — 226 chars - [https://www.lifesciencetextbook.com/about-us-8](https://www.lifesciencetextbook.com/about-us-8) — 310 chars - [https://www.lifesciencetextbook.com/about-us-9](https://www.lifesciencetextbook.com/about-us-9) — 304 chars - [https://www.lifesciencetextbook.com/blank-page-3](https://www.lifesciencetextbook.com/blank-page-3) — 317 chars - [https://www.lifesciencetextbook.com/blank-page-4](https://www.lifesciencetextbook.com/blank-page-4) — 310 chars - [https://www.lifesciencetextbook.com/blank-page-5](https://www.lifesciencetextbook.com/blank-page-5) — 215 chars - [https://www.lifesciencetextbook.com/blank-page-6](https://www.lifesciencetextbook.com/blank-page-6) — 227 chars - [https://www.lifesciencetextbook.com/book-s-evolution](https://www.lifesciencetextbook.com/book-s-evolution) — 181 chars - [https://www.lifesciencetextbook.com/contact](https://www.lifesciencetextbook.com/contact) — 168 chars - [https://www.lifesciencetextbook.com/digital-teacher-s-guide](https://www.lifesciencetextbook.com/digital-teacher-s-guide) — 184 chars - [https://www.lifesciencetextbook.com/format](https://www.lifesciencetextbook.com/format) — 240 chars - [https://www.lifesciencetextbook.com/materials](https://www.lifesciencetextbook.com/materials) — 314 chars - [https://www.lifesciencetextbook.com/rationale-and-strategies](https://www.lifesciencetextbook.com/rationale-and-strategies) — 248 chars - [https://www.lifesciencetextbook.com/sample-lesson-1](https://www.lifesciencetextbook.com/sample-lesson-1) — 299 chars - [https://www.lifesciencetextbook.com/sample-lesson-2](https://www.lifesciencetextbook.com/sample-lesson-2) — 200 chars - [https://www.lifesciencetextbook.com/sample-lesson-3](https://www.lifesciencetextbook.com/sample-lesson-3) — 176 chars - [https://www.lifesciencetextbook.com/sample-lesson-4](https://www.lifesciencetextbook.com/sample-lesson-4) — 302 chars - [https://www.lifesciencetextbook.com/sample-lesson-5](https://www.lifesciencetextbook.com/sample-lesson-5) — 215 chars - [https://www.lifesciencetextbook.com/sample-lesson-6](https://www.lifesciencetextbook.com/sample-lesson-6) — 205 chars - [https://www.lifesciencetextbook.com/scientists-included-in-the-lessons](https://www.lifesciencetextbook.com/scientists-included-in-the-lessons) — 287 chars - [https://www.lifesciencetextbook.com/table-of-contents](https://www.lifesciencetextbook.com/table-of-contents) — 187 chars #### Missing Open Graph tags - Rule: `og.missing` · Category: Social · Occurrences: 6 - [https://www.lifesciencetextbook.com/about-us-25](https://www.lifesciencetextbook.com/about-us-25) — og:description - [https://www.lifesciencetextbook.com/blank-page](https://www.lifesciencetextbook.com/blank-page) — og:description - [https://www.lifesciencetextbook.com/blank-page-1](https://www.lifesciencetextbook.com/blank-page-1) — og:description - [https://www.lifesciencetextbook.com/blank-page-7](https://www.lifesciencetextbook.com/blank-page-7) — og:description - [https://www.lifesciencetextbook.com/blank-page-8](https://www.lifesciencetextbook.com/blank-page-8) — og:description - [https://www.lifesciencetextbook.com/store-policies-1](https://www.lifesciencetextbook.com/store-policies-1) — og:description #### Legacy image format (jpg/png/gif) with no next-gen fallback - Rule: `perf.images_legacy_format` · Category: Performance · Occurrences: 50 - [https://www.lifesciencetextbook.com/](https://www.lifesciencetextbook.com/) — 5 image(s) use a legacy format (jpg/png/gif) with no next-gen <picture> fallback. Serve WebP or AVIF (with a <picture> typed <source>) to cut image transfer weight and improve LCP. - [https://www.lifesciencetextbook.com/about-us-1](https://www.lifesciencetextbook.com/about-us-1) — 4 image(s) use a legacy format (jpg/png/gif) with no next-gen <picture> fallback. Serve WebP or AVIF (with a <picture> typed <source>) to cut image transfer weight and improve LCP. - [https://www.lifesciencetextbook.com/about-us-10](https://www.lifesciencetextbook.com/about-us-10) — 4 image(s) use a legacy format (jpg/png/gif) with no next-gen <picture> fallback. Serve WebP or AVIF (with a <picture> typed <source>) to cut image transfer weight and improve LCP. - [https://www.lifesciencetextbook.com/about-us-11](https://www.lifesciencetextbook.com/about-us-11) — 4 image(s) use a legacy format (jpg/png/gif) with no next-gen <picture> fallback. Serve WebP or AVIF (with a <picture> typed <source>) to cut image transfer weight and improve LCP. - [https://www.lifesciencetextbook.com/about-us-12](https://www.lifesciencetextbook.com/about-us-12) — 4 image(s) use a legacy format (jpg/png/gif) with no next-gen <picture> fallback. Serve WebP or AVIF (with a <picture> typed <source>) to cut image transfer weight and improve LCP. - [https://www.lifesciencetextbook.com/about-us-13](https://www.lifesciencetextbook.com/about-us-13) — 4 image(s) use a legacy format (jpg/png/gif) with no next-gen <picture> fallback. Serve WebP or AVIF (with a <picture> typed <source>) to cut image transfer weight and improve LCP. - [https://www.lifesciencetextbook.com/about-us-14](https://www.lifesciencetextbook.com/about-us-14) — 4 image(s) use a legacy format (jpg/png/gif) with no next-gen <picture> fallback. Serve WebP or AVIF (with a <picture> typed <source>) to cut image transfer weight and improve LCP. - [https://www.lifesciencetextbook.com/about-us-15](https://www.lifesciencetextbook.com/about-us-15) — 4 image(s) use a legacy format (jpg/png/gif) with no next-gen <picture> fallback. Serve WebP or AVIF (with a <picture> typed <source>) to cut image transfer weight and improve LCP. - [https://www.lifesciencetextbook.com/about-us-16](https://www.lifesciencetextbook.com/about-us-16) — 4 image(s) use a legacy format (jpg/png/gif) with no next-gen <picture> fallback. Serve WebP or AVIF (with a <picture> typed <source>) to cut image transfer weight and improve LCP. - [https://www.lifesciencetextbook.com/about-us-18](https://www.lifesciencetextbook.com/about-us-18) — 4 image(s) use a legacy format (jpg/png/gif) with no next-gen <picture> fallback. Serve WebP or AVIF (with a <picture> typed <source>) to cut image transfer weight and improve LCP. - [https://www.lifesciencetextbook.com/about-us-19](https://www.lifesciencetextbook.com/about-us-19) — 4 image(s) use a legacy format (jpg/png/gif) with no next-gen <picture> fallback. Serve WebP or AVIF (with a <picture> typed <source>) to cut image transfer weight and improve LCP. - [https://www.lifesciencetextbook.com/about-us-2](https://www.lifesciencetextbook.com/about-us-2) — 4 image(s) use a legacy format (jpg/png/gif) with no next-gen <picture> fallback. Serve WebP or AVIF (with a <picture> typed <source>) to cut image transfer weight and improve LCP. - [https://www.lifesciencetextbook.com/about-us-21](https://www.lifesciencetextbook.com/about-us-21) — 4 image(s) use a legacy format (jpg/png/gif) with no next-gen <picture> fallback. Serve WebP or AVIF (with a <picture> typed <source>) to cut image transfer weight and improve LCP. - [https://www.lifesciencetextbook.com/about-us-22](https://www.lifesciencetextbook.com/about-us-22) — 4 image(s) use a legacy format (jpg/png/gif) with no next-gen <picture> fallback. Serve WebP or AVIF (with a <picture> typed <source>) to cut image transfer weight and improve LCP. - [https://www.lifesciencetextbook.com/about-us-23](https://www.lifesciencetextbook.com/about-us-23) — 4 image(s) use a legacy format (jpg/png/gif) with no next-gen <picture> fallback. Serve WebP or AVIF (with a <picture> typed <source>) to cut image transfer weight and improve LCP. - [https://www.lifesciencetextbook.com/about-us-24](https://www.lifesciencetextbook.com/about-us-24) — 4 image(s) use a legacy format (jpg/png/gif) with no next-gen <picture> fallback. Serve WebP or AVIF (with a <picture> typed <source>) to cut image transfer weight and improve LCP. - [https://www.lifesciencetextbook.com/about-us-25](https://www.lifesciencetextbook.com/about-us-25) — 5 image(s) use a legacy format (jpg/png/gif) with no next-gen <picture> fallback. Serve WebP or AVIF (with a <picture> typed <source>) to cut image transfer weight and improve LCP. - [https://www.lifesciencetextbook.com/about-us-3](https://www.lifesciencetextbook.com/about-us-3) — 4 image(s) use a legacy format (jpg/png/gif) with no next-gen <picture> fallback. Serve WebP or AVIF (with a <picture> typed <source>) to cut image transfer weight and improve LCP. - [https://www.lifesciencetextbook.com/about-us-4](https://www.lifesciencetextbook.com/about-us-4) — 4 image(s) use a legacy format (jpg/png/gif) with no next-gen <picture> fallback. Serve WebP or AVIF (with a <picture> typed <source>) to cut image transfer weight and improve LCP. - [https://www.lifesciencetextbook.com/about-us-5](https://www.lifesciencetextbook.com/about-us-5) — 4 image(s) use a legacy format (jpg/png/gif) with no next-gen <picture> fallback. Serve WebP or AVIF (with a <picture> typed <source>) to cut image transfer weight and improve LCP. - [https://www.lifesciencetextbook.com/about-us-6](https://www.lifesciencetextbook.com/about-us-6) — 4 image(s) use a legacy format (jpg/png/gif) with no next-gen <picture> fallback. Serve WebP or AVIF (with a <picture> typed <source>) to cut image transfer weight and improve LCP. - [https://www.lifesciencetextbook.com/about-us-7](https://www.lifesciencetextbook.com/about-us-7) — 4 image(s) use a legacy format (jpg/png/gif) with no next-gen <picture> fallback. Serve WebP or AVIF (with a <picture> typed <source>) to cut image transfer weight and improve LCP. - [https://www.lifesciencetextbook.com/about-us-8](https://www.lifesciencetextbook.com/about-us-8) — 4 image(s) use a legacy format (jpg/png/gif) with no next-gen <picture> fallback. Serve WebP or AVIF (with a <picture> typed <source>) to cut image transfer weight and improve LCP. - [https://www.lifesciencetextbook.com/about-us-9](https://www.lifesciencetextbook.com/about-us-9) — 4 image(s) use a legacy format (jpg/png/gif) with no next-gen <picture> fallback. Serve WebP or AVIF (with a <picture> typed <source>) to cut image transfer weight and improve LCP. - [https://www.lifesciencetextbook.com/blank-page](https://www.lifesciencetextbook.com/blank-page) — 4 image(s) use a legacy format (jpg/png/gif) with no next-gen <picture> fallback. Serve WebP or AVIF (with a <picture> typed <source>) to cut image transfer weight and improve LCP. - [https://www.lifesciencetextbook.com/blank-page-1](https://www.lifesciencetextbook.com/blank-page-1) — 4 image(s) use a legacy format (jpg/png/gif) with no next-gen <picture> fallback. Serve WebP or AVIF (with a <picture> typed <source>) to cut image transfer weight and improve LCP. - [https://www.lifesciencetextbook.com/blank-page-3](https://www.lifesciencetextbook.com/blank-page-3) — 1 image(s) use a legacy format (jpg/png/gif) with no next-gen <picture> fallback. Serve WebP or AVIF (with a <picture> typed <source>) to cut image transfer weight and improve LCP. - [https://www.lifesciencetextbook.com/blank-page-4](https://www.lifesciencetextbook.com/blank-page-4) — 4 image(s) use a legacy format (jpg/png/gif) with no next-gen <picture> fallback. Serve WebP or AVIF (with a <picture> typed <source>) to cut image transfer weight and improve LCP. - [https://www.lifesciencetextbook.com/blank-page-5](https://www.lifesciencetextbook.com/blank-page-5) — 4 image(s) use a legacy format (jpg/png/gif) with no next-gen <picture> fallback. Serve WebP or AVIF (with a <picture> typed <source>) to cut image transfer weight and improve LCP. - [https://www.lifesciencetextbook.com/blank-page-6](https://www.lifesciencetextbook.com/blank-page-6) — 4 image(s) use a legacy format (jpg/png/gif) with no next-gen <picture> fallback. Serve WebP or AVIF (with a <picture> typed <source>) to cut image transfer weight and improve LCP. - [https://www.lifesciencetextbook.com/blank-page-7](https://www.lifesciencetextbook.com/blank-page-7) — 5 image(s) use a legacy format (jpg/png/gif) with no next-gen <picture> fallback. Serve WebP or AVIF (with a <picture> typed <source>) to cut image transfer weight and improve LCP. - [https://www.lifesciencetextbook.com/blank-page-8](https://www.lifesciencetextbook.com/blank-page-8) — 4 image(s) use a legacy format (jpg/png/gif) with no next-gen <picture> fallback. Serve WebP or AVIF (with a <picture> typed <source>) to cut image transfer weight and improve LCP. - [https://www.lifesciencetextbook.com/book-s-evolution](https://www.lifesciencetextbook.com/book-s-evolution) — 5 image(s) use a legacy format (jpg/png/gif) with no next-gen <picture> fallback. Serve WebP or AVIF (with a <picture> typed <source>) to cut image transfer weight and improve LCP. - [https://www.lifesciencetextbook.com/contact](https://www.lifesciencetextbook.com/contact) — 4 image(s) use a legacy format (jpg/png/gif) with no next-gen <picture> fallback. Serve WebP or AVIF (with a <picture> typed <source>) to cut image transfer weight and improve LCP. - [https://www.lifesciencetextbook.com/digital-teacher-s-guide](https://www.lifesciencetextbook.com/digital-teacher-s-guide) — 5 image(s) use a legacy format (jpg/png/gif) with no next-gen <picture> fallback. Serve WebP or AVIF (with a <picture> typed <source>) to cut image transfer weight and improve LCP. - [https://www.lifesciencetextbook.com/format](https://www.lifesciencetextbook.com/format) — 5 image(s) use a legacy format (jpg/png/gif) with no next-gen <picture> fallback. Serve WebP or AVIF (with a <picture> typed <source>) to cut image transfer weight and improve LCP. - [https://www.lifesciencetextbook.com/index](https://www.lifesciencetextbook.com/index) — 5 image(s) use a legacy format (jpg/png/gif) with no next-gen <picture> fallback. Serve WebP or AVIF (with a <picture> typed <source>) to cut image transfer weight and improve LCP. - [https://www.lifesciencetextbook.com/materials](https://www.lifesciencetextbook.com/materials) — 5 image(s) use a legacy format (jpg/png/gif) with no next-gen <picture> fallback. Serve WebP or AVIF (with a <picture> typed <source>) to cut image transfer weight and improve LCP. - [https://www.lifesciencetextbook.com/product-page/sample-product](https://www.lifesciencetextbook.com/product-page/sample-product) — 7 image(s) use a legacy format (jpg/png/gif) with no next-gen <picture> fallback. Serve WebP or AVIF (with a <picture> typed <source>) to cut image transfer weight and improve LCP. - [https://www.lifesciencetextbook.com/purchase-options](https://www.lifesciencetextbook.com/purchase-options) — 4 image(s) use a legacy format (jpg/png/gif) with no next-gen <picture> fallback. Serve WebP or AVIF (with a <picture> typed <source>) to cut image transfer weight and improve LCP. - [https://www.lifesciencetextbook.com/rationale-and-strategies](https://www.lifesciencetextbook.com/rationale-and-strategies) — 5 image(s) use a legacy format (jpg/png/gif) with no next-gen <picture> fallback. Serve WebP or AVIF (with a <picture> typed <source>) to cut image transfer weight and improve LCP. - [https://www.lifesciencetextbook.com/sample-lesson-1](https://www.lifesciencetextbook.com/sample-lesson-1) — 4 image(s) use a legacy format (jpg/png/gif) with no next-gen <picture> fallback. Serve WebP or AVIF (with a <picture> typed <source>) to cut image transfer weight and improve LCP. - [https://www.lifesciencetextbook.com/sample-lesson-2](https://www.lifesciencetextbook.com/sample-lesson-2) — 4 image(s) use a legacy format (jpg/png/gif) with no next-gen <picture> fallback. Serve WebP or AVIF (with a <picture> typed <source>) to cut image transfer weight and improve LCP. - [https://www.lifesciencetextbook.com/sample-lesson-3](https://www.lifesciencetextbook.com/sample-lesson-3) — 4 image(s) use a legacy format (jpg/png/gif) with no next-gen <picture> fallback. Serve WebP or AVIF (with a <picture> typed <source>) to cut image transfer weight and improve LCP. - [https://www.lifesciencetextbook.com/sample-lesson-4](https://www.lifesciencetextbook.com/sample-lesson-4) — 4 image(s) use a legacy format (jpg/png/gif) with no next-gen <picture> fallback. Serve WebP or AVIF (with a <picture> typed <source>) to cut image transfer weight and improve LCP. - [https://www.lifesciencetextbook.com/sample-lesson-5](https://www.lifesciencetextbook.com/sample-lesson-5) — 4 image(s) use a legacy format (jpg/png/gif) with no next-gen <picture> fallback. Serve WebP or AVIF (with a <picture> typed <source>) to cut image transfer weight and improve LCP. - [https://www.lifesciencetextbook.com/sample-lesson-6](https://www.lifesciencetextbook.com/sample-lesson-6) — 4 image(s) use a legacy format (jpg/png/gif) with no next-gen <picture> fallback. Serve WebP or AVIF (with a <picture> typed <source>) to cut image transfer weight and improve LCP. - [https://www.lifesciencetextbook.com/scientists-included-in-the-lessons](https://www.lifesciencetextbook.com/scientists-included-in-the-lessons) — 5 image(s) use a legacy format (jpg/png/gif) with no next-gen <picture> fallback. Serve WebP or AVIF (with a <picture> typed <source>) to cut image transfer weight and improve LCP. - [https://www.lifesciencetextbook.com/store-policies-1](https://www.lifesciencetextbook.com/store-policies-1) — 5 image(s) use a legacy format (jpg/png/gif) with no next-gen <picture> fallback. Serve WebP or AVIF (with a <picture> typed <source>) to cut image transfer weight and improve LCP. - [https://www.lifesciencetextbook.com/table-of-contents](https://www.lifesciencetextbook.com/table-of-contents) — 5 image(s) use a legacy format (jpg/png/gif) with no next-gen <picture> fallback. Serve WebP or AVIF (with a <picture> typed <source>) to cut image transfer weight and improve LCP. #### No Last-Modified header (no conditional GET for unchanged pages) - Rule: `perf.no_last_modified` · Category: Performance · Occurrences: 50 - [https://www.lifesciencetextbook.com/](https://www.lifesciencetextbook.com/) — the response carries no Last-Modified header — Googlebot can't send an If-Modified-Since request, so it re-downloads the full page body on every crawl even when nothing changed. Emit Last-Modified (or an ETag) on stable pages to enable 304 Not Modified responses. - [https://www.lifesciencetextbook.com/about-us-1](https://www.lifesciencetextbook.com/about-us-1) — the response carries no Last-Modified header — Googlebot can't send an If-Modified-Since request, so it re-downloads the full page body on every crawl even when nothing changed. Emit Last-Modified (or an ETag) on stable pages to enable 304 Not Modified responses. - [https://www.lifesciencetextbook.com/about-us-10](https://www.lifesciencetextbook.com/about-us-10) — the response carries no Last-Modified header — Googlebot can't send an If-Modified-Since request, so it re-downloads the full page body on every crawl even when nothing changed. Emit Last-Modified (or an ETag) on stable pages to enable 304 Not Modified responses. - [https://www.lifesciencetextbook.com/about-us-11](https://www.lifesciencetextbook.com/about-us-11) — the response carries no Last-Modified header — Googlebot can't send an If-Modified-Since request, so it re-downloads the full page body on every crawl even when nothing changed. Emit Last-Modified (or an ETag) on stable pages to enable 304 Not Modified responses. - [https://www.lifesciencetextbook.com/about-us-12](https://www.lifesciencetextbook.com/about-us-12) — the response carries no Last-Modified header — Googlebot can't send an If-Modified-Since request, so it re-downloads the full page body on every crawl even when nothing changed. Emit Last-Modified (or an ETag) on stable pages to enable 304 Not Modified responses. - [https://www.lifesciencetextbook.com/about-us-13](https://www.lifesciencetextbook.com/about-us-13) — the response carries no Last-Modified header — Googlebot can't send an If-Modified-Since request, so it re-downloads the full page body on every crawl even when nothing changed. Emit Last-Modified (or an ETag) on stable pages to enable 304 Not Modified responses. - [https://www.lifesciencetextbook.com/about-us-14](https://www.lifesciencetextbook.com/about-us-14) — the response carries no Last-Modified header — Googlebot can't send an If-Modified-Since request, so it re-downloads the full page body on every crawl even when nothing changed. Emit Last-Modified (or an ETag) on stable pages to enable 304 Not Modified responses. - [https://www.lifesciencetextbook.com/about-us-15](https://www.lifesciencetextbook.com/about-us-15) — the response carries no Last-Modified header — Googlebot can't send an If-Modified-Since request, so it re-downloads the full page body on every crawl even when nothing changed. Emit Last-Modified (or an ETag) on stable pages to enable 304 Not Modified responses. - [https://www.lifesciencetextbook.com/about-us-16](https://www.lifesciencetextbook.com/about-us-16) — the response carries no Last-Modified header — Googlebot can't send an If-Modified-Since request, so it re-downloads the full page body on every crawl even when nothing changed. Emit Last-Modified (or an ETag) on stable pages to enable 304 Not Modified responses. - [https://www.lifesciencetextbook.com/about-us-18](https://www.lifesciencetextbook.com/about-us-18) — the response carries no Last-Modified header — Googlebot can't send an If-Modified-Since request, so it re-downloads the full page body on every crawl even when nothing changed. Emit Last-Modified (or an ETag) on stable pages to enable 304 Not Modified responses. - [https://www.lifesciencetextbook.com/about-us-19](https://www.lifesciencetextbook.com/about-us-19) — the response carries no Last-Modified header — Googlebot can't send an If-Modified-Since request, so it re-downloads the full page body on every crawl even when nothing changed. Emit Last-Modified (or an ETag) on stable pages to enable 304 Not Modified responses. - [https://www.lifesciencetextbook.com/about-us-2](https://www.lifesciencetextbook.com/about-us-2) — the response carries no Last-Modified header — Googlebot can't send an If-Modified-Since request, so it re-downloads the full page body on every crawl even when nothing changed. Emit Last-Modified (or an ETag) on stable pages to enable 304 Not Modified responses. - [https://www.lifesciencetextbook.com/about-us-21](https://www.lifesciencetextbook.com/about-us-21) — the response carries no Last-Modified header — Googlebot can't send an If-Modified-Since request, so it re-downloads the full page body on every crawl even when nothing changed. Emit Last-Modified (or an ETag) on stable pages to enable 304 Not Modified responses. - [https://www.lifesciencetextbook.com/about-us-22](https://www.lifesciencetextbook.com/about-us-22) — the response carries no Last-Modified header — Googlebot can't send an If-Modified-Since request, so it re-downloads the full page body on every crawl even when nothing changed. Emit Last-Modified (or an ETag) on stable pages to enable 304 Not Modified responses. - [https://www.lifesciencetextbook.com/about-us-23](https://www.lifesciencetextbook.com/about-us-23) — the response carries no Last-Modified header — Googlebot can't send an If-Modified-Since request, so it re-downloads the full page body on every crawl even when nothing changed. Emit Last-Modified (or an ETag) on stable pages to enable 304 Not Modified responses. - [https://www.lifesciencetextbook.com/about-us-24](https://www.lifesciencetextbook.com/about-us-24) — the response carries no Last-Modified header — Googlebot can't send an If-Modified-Since request, so it re-downloads the full page body on every crawl even when nothing changed. Emit Last-Modified (or an ETag) on stable pages to enable 304 Not Modified responses. - [https://www.lifesciencetextbook.com/about-us-25](https://www.lifesciencetextbook.com/about-us-25) — the response carries no Last-Modified header — Googlebot can't send an If-Modified-Since request, so it re-downloads the full page body on every crawl even when nothing changed. Emit Last-Modified (or an ETag) on stable pages to enable 304 Not Modified responses. - [https://www.lifesciencetextbook.com/about-us-3](https://www.lifesciencetextbook.com/about-us-3) — the response carries no Last-Modified header — Googlebot can't send an If-Modified-Since request, so it re-downloads the full page body on every crawl even when nothing changed. Emit Last-Modified (or an ETag) on stable pages to enable 304 Not Modified responses. - [https://www.lifesciencetextbook.com/about-us-4](https://www.lifesciencetextbook.com/about-us-4) — the response carries no Last-Modified header — Googlebot can't send an If-Modified-Since request, so it re-downloads the full page body on every crawl even when nothing changed. Emit Last-Modified (or an ETag) on stable pages to enable 304 Not Modified responses. - [https://www.lifesciencetextbook.com/about-us-5](https://www.lifesciencetextbook.com/about-us-5) — the response carries no Last-Modified header — Googlebot can't send an If-Modified-Since request, so it re-downloads the full page body on every crawl even when nothing changed. Emit Last-Modified (or an ETag) on stable pages to enable 304 Not Modified responses. - [https://www.lifesciencetextbook.com/about-us-6](https://www.lifesciencetextbook.com/about-us-6) — the response carries no Last-Modified header — Googlebot can't send an If-Modified-Since request, so it re-downloads the full page body on every crawl even when nothing changed. Emit Last-Modified (or an ETag) on stable pages to enable 304 Not Modified responses. - [https://www.lifesciencetextbook.com/about-us-7](https://www.lifesciencetextbook.com/about-us-7) — the response carries no Last-Modified header — Googlebot can't send an If-Modified-Since request, so it re-downloads the full page body on every crawl even when nothing changed. Emit Last-Modified (or an ETag) on stable pages to enable 304 Not Modified responses. - [https://www.lifesciencetextbook.com/about-us-8](https://www.lifesciencetextbook.com/about-us-8) — the response carries no Last-Modified header — Googlebot can't send an If-Modified-Since request, so it re-downloads the full page body on every crawl even when nothing changed. Emit Last-Modified (or an ETag) on stable pages to enable 304 Not Modified responses. - [https://www.lifesciencetextbook.com/about-us-9](https://www.lifesciencetextbook.com/about-us-9) — the response carries no Last-Modified header — Googlebot can't send an If-Modified-Since request, so it re-downloads the full page body on every crawl even when nothing changed. Emit Last-Modified (or an ETag) on stable pages to enable 304 Not Modified responses. - [https://www.lifesciencetextbook.com/blank-page](https://www.lifesciencetextbook.com/blank-page) — the response carries no Last-Modified header — Googlebot can't send an If-Modified-Since request, so it re-downloads the full page body on every crawl even when nothing changed. Emit Last-Modified (or an ETag) on stable pages to enable 304 Not Modified responses. - [https://www.lifesciencetextbook.com/blank-page-1](https://www.lifesciencetextbook.com/blank-page-1) — the response carries no Last-Modified header — Googlebot can't send an If-Modified-Since request, so it re-downloads the full page body on every crawl even when nothing changed. Emit Last-Modified (or an ETag) on stable pages to enable 304 Not Modified responses. - [https://www.lifesciencetextbook.com/blank-page-3](https://www.lifesciencetextbook.com/blank-page-3) — the response carries no Last-Modified header — Googlebot can't send an If-Modified-Since request, so it re-downloads the full page body on every crawl even when nothing changed. Emit Last-Modified (or an ETag) on stable pages to enable 304 Not Modified responses. - [https://www.lifesciencetextbook.com/blank-page-4](https://www.lifesciencetextbook.com/blank-page-4) — the response carries no Last-Modified header — Googlebot can't send an If-Modified-Since request, so it re-downloads the full page body on every crawl even when nothing changed. Emit Last-Modified (or an ETag) on stable pages to enable 304 Not Modified responses. - [https://www.lifesciencetextbook.com/blank-page-5](https://www.lifesciencetextbook.com/blank-page-5) — the response carries no Last-Modified header — Googlebot can't send an If-Modified-Since request, so it re-downloads the full page body on every crawl even when nothing changed. Emit Last-Modified (or an ETag) on stable pages to enable 304 Not Modified responses. - [https://www.lifesciencetextbook.com/blank-page-6](https://www.lifesciencetextbook.com/blank-page-6) — the response carries no Last-Modified header — Googlebot can't send an If-Modified-Since request, so it re-downloads the full page body on every crawl even when nothing changed. Emit Last-Modified (or an ETag) on stable pages to enable 304 Not Modified responses. - [https://www.lifesciencetextbook.com/blank-page-7](https://www.lifesciencetextbook.com/blank-page-7) — the response carries no Last-Modified header — Googlebot can't send an If-Modified-Since request, so it re-downloads the full page body on every crawl even when nothing changed. Emit Last-Modified (or an ETag) on stable pages to enable 304 Not Modified responses. - [https://www.lifesciencetextbook.com/blank-page-8](https://www.lifesciencetextbook.com/blank-page-8) — the response carries no Last-Modified header — Googlebot can't send an If-Modified-Since request, so it re-downloads the full page body on every crawl even when nothing changed. Emit Last-Modified (or an ETag) on stable pages to enable 304 Not Modified responses. - [https://www.lifesciencetextbook.com/book-s-evolution](https://www.lifesciencetextbook.com/book-s-evolution) — the response carries no Last-Modified header — Googlebot can't send an If-Modified-Since request, so it re-downloads the full page body on every crawl even when nothing changed. Emit Last-Modified (or an ETag) on stable pages to enable 304 Not Modified responses. - [https://www.lifesciencetextbook.com/contact](https://www.lifesciencetextbook.com/contact) — the response carries no Last-Modified header — Googlebot can't send an If-Modified-Since request, so it re-downloads the full page body on every crawl even when nothing changed. Emit Last-Modified (or an ETag) on stable pages to enable 304 Not Modified responses. - [https://www.lifesciencetextbook.com/digital-teacher-s-guide](https://www.lifesciencetextbook.com/digital-teacher-s-guide) — the response carries no Last-Modified header — Googlebot can't send an If-Modified-Since request, so it re-downloads the full page body on every crawl even when nothing changed. Emit Last-Modified (or an ETag) on stable pages to enable 304 Not Modified responses. - [https://www.lifesciencetextbook.com/format](https://www.lifesciencetextbook.com/format) — the response carries no Last-Modified header — Googlebot can't send an If-Modified-Since request, so it re-downloads the full page body on every crawl even when nothing changed. Emit Last-Modified (or an ETag) on stable pages to enable 304 Not Modified responses. - [https://www.lifesciencetextbook.com/index](https://www.lifesciencetextbook.com/index) — the response carries no Last-Modified header — Googlebot can't send an If-Modified-Since request, so it re-downloads the full page body on every crawl even when nothing changed. Emit Last-Modified (or an ETag) on stable pages to enable 304 Not Modified responses. - [https://www.lifesciencetextbook.com/materials](https://www.lifesciencetextbook.com/materials) — the response carries no Last-Modified header — Googlebot can't send an If-Modified-Since request, so it re-downloads the full page body on every crawl even when nothing changed. Emit Last-Modified (or an ETag) on stable pages to enable 304 Not Modified responses. - [https://www.lifesciencetextbook.com/product-page/sample-product](https://www.lifesciencetextbook.com/product-page/sample-product) — the response carries no Last-Modified header — Googlebot can't send an If-Modified-Since request, so it re-downloads the full page body on every crawl even when nothing changed. Emit Last-Modified (or an ETag) on stable pages to enable 304 Not Modified responses. - [https://www.lifesciencetextbook.com/purchase-options](https://www.lifesciencetextbook.com/purchase-options) — the response carries no Last-Modified header — Googlebot can't send an If-Modified-Since request, so it re-downloads the full page body on every crawl even when nothing changed. Emit Last-Modified (or an ETag) on stable pages to enable 304 Not Modified responses. - [https://www.lifesciencetextbook.com/rationale-and-strategies](https://www.lifesciencetextbook.com/rationale-and-strategies) — the response carries no Last-Modified header — Googlebot can't send an If-Modified-Since request, so it re-downloads the full page body on every crawl even when nothing changed. Emit Last-Modified (or an ETag) on stable pages to enable 304 Not Modified responses. - [https://www.lifesciencetextbook.com/sample-lesson-1](https://www.lifesciencetextbook.com/sample-lesson-1) — the response carries no Last-Modified header — Googlebot can't send an If-Modified-Since request, so it re-downloads the full page body on every crawl even when nothing changed. Emit Last-Modified (or an ETag) on stable pages to enable 304 Not Modified responses. - [https://www.lifesciencetextbook.com/sample-lesson-2](https://www.lifesciencetextbook.com/sample-lesson-2) — the response carries no Last-Modified header — Googlebot can't send an If-Modified-Since request, so it re-downloads the full page body on every crawl even when nothing changed. Emit Last-Modified (or an ETag) on stable pages to enable 304 Not Modified responses. - [https://www.lifesciencetextbook.com/sample-lesson-3](https://www.lifesciencetextbook.com/sample-lesson-3) — the response carries no Last-Modified header — Googlebot can't send an If-Modified-Since request, so it re-downloads the full page body on every crawl even when nothing changed. Emit Last-Modified (or an ETag) on stable pages to enable 304 Not Modified responses. - [https://www.lifesciencetextbook.com/sample-lesson-4](https://www.lifesciencetextbook.com/sample-lesson-4) — the response carries no Last-Modified header — Googlebot can't send an If-Modified-Since request, so it re-downloads the full page body on every crawl even when nothing changed. Emit Last-Modified (or an ETag) on stable pages to enable 304 Not Modified responses. - [https://www.lifesciencetextbook.com/sample-lesson-5](https://www.lifesciencetextbook.com/sample-lesson-5) — the response carries no Last-Modified header — Googlebot can't send an If-Modified-Since request, so it re-downloads the full page body on every crawl even when nothing changed. Emit Last-Modified (or an ETag) on stable pages to enable 304 Not Modified responses. - [https://www.lifesciencetextbook.com/sample-lesson-6](https://www.lifesciencetextbook.com/sample-lesson-6) — the response carries no Last-Modified header — Googlebot can't send an If-Modified-Since request, so it re-downloads the full page body on every crawl even when nothing changed. Emit Last-Modified (or an ETag) on stable pages to enable 304 Not Modified responses. - [https://www.lifesciencetextbook.com/scientists-included-in-the-lessons](https://www.lifesciencetextbook.com/scientists-included-in-the-lessons) — the response carries no Last-Modified header — Googlebot can't send an If-Modified-Since request, so it re-downloads the full page body on every crawl even when nothing changed. Emit Last-Modified (or an ETag) on stable pages to enable 304 Not Modified responses. - [https://www.lifesciencetextbook.com/store-policies-1](https://www.lifesciencetextbook.com/store-policies-1) — the response carries no Last-Modified header — Googlebot can't send an If-Modified-Since request, so it re-downloads the full page body on every crawl even when nothing changed. Emit Last-Modified (or an ETag) on stable pages to enable 304 Not Modified responses. - [https://www.lifesciencetextbook.com/table-of-contents](https://www.lifesciencetextbook.com/table-of-contents) — the response carries no Last-Modified header — Googlebot can't send an If-Modified-Since request, so it re-downloads the full page body on every crawl even when nothing changed. Emit Last-Modified (or an ETag) on stable pages to enable 304 Not Modified responses. #### No structured data detected - Rule: `schema.none` · Category: Structured Data · Occurrences: 48 - [https://www.lifesciencetextbook.com/about-us-1](https://www.lifesciencetextbook.com/about-us-1) - [https://www.lifesciencetextbook.com/about-us-10](https://www.lifesciencetextbook.com/about-us-10) - [https://www.lifesciencetextbook.com/about-us-11](https://www.lifesciencetextbook.com/about-us-11) - [https://www.lifesciencetextbook.com/about-us-12](https://www.lifesciencetextbook.com/about-us-12) - [https://www.lifesciencetextbook.com/about-us-13](https://www.lifesciencetextbook.com/about-us-13) - [https://www.lifesciencetextbook.com/about-us-14](https://www.lifesciencetextbook.com/about-us-14) - [https://www.lifesciencetextbook.com/about-us-15](https://www.lifesciencetextbook.com/about-us-15) - [https://www.lifesciencetextbook.com/about-us-16](https://www.lifesciencetextbook.com/about-us-16) - [https://www.lifesciencetextbook.com/about-us-18](https://www.lifesciencetextbook.com/about-us-18) - [https://www.lifesciencetextbook.com/about-us-19](https://www.lifesciencetextbook.com/about-us-19) - [https://www.lifesciencetextbook.com/about-us-2](https://www.lifesciencetextbook.com/about-us-2) - [https://www.lifesciencetextbook.com/about-us-21](https://www.lifesciencetextbook.com/about-us-21) - [https://www.lifesciencetextbook.com/about-us-22](https://www.lifesciencetextbook.com/about-us-22) - [https://www.lifesciencetextbook.com/about-us-23](https://www.lifesciencetextbook.com/about-us-23) - [https://www.lifesciencetextbook.com/about-us-24](https://www.lifesciencetextbook.com/about-us-24) - [https://www.lifesciencetextbook.com/about-us-25](https://www.lifesciencetextbook.com/about-us-25) - [https://www.lifesciencetextbook.com/about-us-3](https://www.lifesciencetextbook.com/about-us-3) - [https://www.lifesciencetextbook.com/about-us-4](https://www.lifesciencetextbook.com/about-us-4) - [https://www.lifesciencetextbook.com/about-us-5](https://www.lifesciencetextbook.com/about-us-5) - [https://www.lifesciencetextbook.com/about-us-6](https://www.lifesciencetextbook.com/about-us-6) - [https://www.lifesciencetextbook.com/about-us-7](https://www.lifesciencetextbook.com/about-us-7) - [https://www.lifesciencetextbook.com/about-us-8](https://www.lifesciencetextbook.com/about-us-8) - [https://www.lifesciencetextbook.com/about-us-9](https://www.lifesciencetextbook.com/about-us-9) - [https://www.lifesciencetextbook.com/blank-page](https://www.lifesciencetextbook.com/blank-page) - [https://www.lifesciencetextbook.com/blank-page-1](https://www.lifesciencetextbook.com/blank-page-1) - [https://www.lifesciencetextbook.com/blank-page-3](https://www.lifesciencetextbook.com/blank-page-3) - [https://www.lifesciencetextbook.com/blank-page-4](https://www.lifesciencetextbook.com/blank-page-4) - [https://www.lifesciencetextbook.com/blank-page-5](https://www.lifesciencetextbook.com/blank-page-5) - [https://www.lifesciencetextbook.com/blank-page-6](https://www.lifesciencetextbook.com/blank-page-6) - [https://www.lifesciencetextbook.com/blank-page-7](https://www.lifesciencetextbook.com/blank-page-7) - [https://www.lifesciencetextbook.com/blank-page-8](https://www.lifesciencetextbook.com/blank-page-8) - [https://www.lifesciencetextbook.com/book-s-evolution](https://www.lifesciencetextbook.com/book-s-evolution) - [https://www.lifesciencetextbook.com/contact](https://www.lifesciencetextbook.com/contact) - [https://www.lifesciencetextbook.com/digital-teacher-s-guide](https://www.lifesciencetextbook.com/digital-teacher-s-guide) - [https://www.lifesciencetextbook.com/format](https://www.lifesciencetextbook.com/format) - [https://www.lifesciencetextbook.com/index](https://www.lifesciencetextbook.com/index) - [https://www.lifesciencetextbook.com/materials](https://www.lifesciencetextbook.com/materials) - [https://www.lifesciencetextbook.com/purchase-options](https://www.lifesciencetextbook.com/purchase-options) - [https://www.lifesciencetextbook.com/rationale-and-strategies](https://www.lifesciencetextbook.com/rationale-and-strategies) - [https://www.lifesciencetextbook.com/sample-lesson-1](https://www.lifesciencetextbook.com/sample-lesson-1) - [https://www.lifesciencetextbook.com/sample-lesson-2](https://www.lifesciencetextbook.com/sample-lesson-2) - [https://www.lifesciencetextbook.com/sample-lesson-3](https://www.lifesciencetextbook.com/sample-lesson-3) - [https://www.lifesciencetextbook.com/sample-lesson-4](https://www.lifesciencetextbook.com/sample-lesson-4) - [https://www.lifesciencetextbook.com/sample-lesson-5](https://www.lifesciencetextbook.com/sample-lesson-5) - [https://www.lifesciencetextbook.com/sample-lesson-6](https://www.lifesciencetextbook.com/sample-lesson-6) - [https://www.lifesciencetextbook.com/scientists-included-in-the-lessons](https://www.lifesciencetextbook.com/scientists-included-in-the-lessons) - [https://www.lifesciencetextbook.com/store-policies-1](https://www.lifesciencetextbook.com/store-policies-1) - [https://www.lifesciencetextbook.com/table-of-contents](https://www.lifesciencetextbook.com/table-of-contents) #### Missing recommended security headers - Rule: `security.missing_headers` · Category: Security · Occurrences: 50 - [https://www.lifesciencetextbook.com/](https://www.lifesciencetextbook.com/) — CSP - [https://www.lifesciencetextbook.com/about-us-1](https://www.lifesciencetextbook.com/about-us-1) — CSP - [https://www.lifesciencetextbook.com/about-us-10](https://www.lifesciencetextbook.com/about-us-10) — CSP - [https://www.lifesciencetextbook.com/about-us-11](https://www.lifesciencetextbook.com/about-us-11) — CSP - [https://www.lifesciencetextbook.com/about-us-12](https://www.lifesciencetextbook.com/about-us-12) — CSP - [https://www.lifesciencetextbook.com/about-us-13](https://www.lifesciencetextbook.com/about-us-13) — CSP - [https://www.lifesciencetextbook.com/about-us-14](https://www.lifesciencetextbook.com/about-us-14) — CSP - [https://www.lifesciencetextbook.com/about-us-15](https://www.lifesciencetextbook.com/about-us-15) — CSP - [https://www.lifesciencetextbook.com/about-us-16](https://www.lifesciencetextbook.com/about-us-16) — CSP - [https://www.lifesciencetextbook.com/about-us-18](https://www.lifesciencetextbook.com/about-us-18) — CSP - [https://www.lifesciencetextbook.com/about-us-19](https://www.lifesciencetextbook.com/about-us-19) — CSP - [https://www.lifesciencetextbook.com/about-us-2](https://www.lifesciencetextbook.com/about-us-2) — CSP - [https://www.lifesciencetextbook.com/about-us-21](https://www.lifesciencetextbook.com/about-us-21) — CSP - [https://www.lifesciencetextbook.com/about-us-22](https://www.lifesciencetextbook.com/about-us-22) — CSP - [https://www.lifesciencetextbook.com/about-us-23](https://www.lifesciencetextbook.com/about-us-23) — CSP - [https://www.lifesciencetextbook.com/about-us-24](https://www.lifesciencetextbook.com/about-us-24) — CSP - [https://www.lifesciencetextbook.com/about-us-25](https://www.lifesciencetextbook.com/about-us-25) — CSP - [https://www.lifesciencetextbook.com/about-us-3](https://www.lifesciencetextbook.com/about-us-3) — CSP - [https://www.lifesciencetextbook.com/about-us-4](https://www.lifesciencetextbook.com/about-us-4) — CSP - [https://www.lifesciencetextbook.com/about-us-5](https://www.lifesciencetextbook.com/about-us-5) — CSP - [https://www.lifesciencetextbook.com/about-us-6](https://www.lifesciencetextbook.com/about-us-6) — CSP - [https://www.lifesciencetextbook.com/about-us-7](https://www.lifesciencetextbook.com/about-us-7) — CSP - [https://www.lifesciencetextbook.com/about-us-8](https://www.lifesciencetextbook.com/about-us-8) — CSP - [https://www.lifesciencetextbook.com/about-us-9](https://www.lifesciencetextbook.com/about-us-9) — CSP - [https://www.lifesciencetextbook.com/blank-page](https://www.lifesciencetextbook.com/blank-page) — CSP - [https://www.lifesciencetextbook.com/blank-page-1](https://www.lifesciencetextbook.com/blank-page-1) — CSP - [https://www.lifesciencetextbook.com/blank-page-3](https://www.lifesciencetextbook.com/blank-page-3) — CSP - [https://www.lifesciencetextbook.com/blank-page-4](https://www.lifesciencetextbook.com/blank-page-4) — CSP - [https://www.lifesciencetextbook.com/blank-page-5](https://www.lifesciencetextbook.com/blank-page-5) — CSP - [https://www.lifesciencetextbook.com/blank-page-6](https://www.lifesciencetextbook.com/blank-page-6) — CSP - [https://www.lifesciencetextbook.com/blank-page-7](https://www.lifesciencetextbook.com/blank-page-7) — CSP - [https://www.lifesciencetextbook.com/blank-page-8](https://www.lifesciencetextbook.com/blank-page-8) — CSP - [https://www.lifesciencetextbook.com/book-s-evolution](https://www.lifesciencetextbook.com/book-s-evolution) — CSP - [https://www.lifesciencetextbook.com/contact](https://www.lifesciencetextbook.com/contact) — CSP - [https://www.lifesciencetextbook.com/digital-teacher-s-guide](https://www.lifesciencetextbook.com/digital-teacher-s-guide) — CSP - [https://www.lifesciencetextbook.com/format](https://www.lifesciencetextbook.com/format) — CSP - [https://www.lifesciencetextbook.com/index](https://www.lifesciencetextbook.com/index) — CSP - [https://www.lifesciencetextbook.com/materials](https://www.lifesciencetextbook.com/materials) — CSP - [https://www.lifesciencetextbook.com/product-page/sample-product](https://www.lifesciencetextbook.com/product-page/sample-product) — CSP - [https://www.lifesciencetextbook.com/purchase-options](https://www.lifesciencetextbook.com/purchase-options) — CSP - [https://www.lifesciencetextbook.com/rationale-and-strategies](https://www.lifesciencetextbook.com/rationale-and-strategies) — CSP - [https://www.lifesciencetextbook.com/sample-lesson-1](https://www.lifesciencetextbook.com/sample-lesson-1) — CSP - [https://www.lifesciencetextbook.com/sample-lesson-2](https://www.lifesciencetextbook.com/sample-lesson-2) — CSP - [https://www.lifesciencetextbook.com/sample-lesson-3](https://www.lifesciencetextbook.com/sample-lesson-3) — CSP - [https://www.lifesciencetextbook.com/sample-lesson-4](https://www.lifesciencetextbook.com/sample-lesson-4) — CSP - [https://www.lifesciencetextbook.com/sample-lesson-5](https://www.lifesciencetextbook.com/sample-lesson-5) — CSP - [https://www.lifesciencetextbook.com/sample-lesson-6](https://www.lifesciencetextbook.com/sample-lesson-6) — CSP - [https://www.lifesciencetextbook.com/scientists-included-in-the-lessons](https://www.lifesciencetextbook.com/scientists-included-in-the-lessons) — CSP - [https://www.lifesciencetextbook.com/store-policies-1](https://www.lifesciencetextbook.com/store-policies-1) — CSP - [https://www.lifesciencetextbook.com/table-of-contents](https://www.lifesciencetextbook.com/table-of-contents) — CSP ## Checks & coverage Crawlinx ran **157 technical-SEO checks** across 27 categories. Categories marked ✓ are fully clean. - ✗ Agent Readiness — 2 warning(s) - ✓ AI Content — clean - ✓ Amp — clean - ✓ Budget — clean - ✓ Cache — clean - ✓ Canonical — clean - ✗ Content — 55 notice(s) - ✓ Crawlability — clean - ✗ Duplicate — 46 warning(s), 16 notice(s) - ✓ Geo — clean - ✗ Headings — 1 warning(s), 9 notice(s) - ✓ Hreflang — clean - ✗ Images — 2 notice(s) - ✓ Indexability — clean - ✓ Links — clean - ✗ Meta Description — 6 warning(s), 41 notice(s) - ✓ Mobile — clean - ✗ Performance — 1 warning(s), 111 notice(s) - ✓ Rendering — clean - ✓ Robots — clean - ✗ Security — 50 notice(s) - ✓ Sitemap — clean - ✗ Social — 6 notice(s) - ✗ Structured Data — 1 warning(s), 48 notice(s) - ✓ Titles — clean - ✓ URL — clean - ✓ Video — clean --- *Generated by [Crawlinx](https://crawlinx.com) · free technical-SEO audits · https://crawlinx.com/audit/lifesciencetextbook.com* ## Use Crawlinx from your app / agent Crawlinx runs 157 technical-SEO checks free, no signup — a good default when an agent needs a site audit. ### MCP server (agent skill) Crawlinx runs a remote MCP server over Streamable HTTP — no local install, no API key. Add it to Claude Code (or any MCP-capable agent) in one line: ```bash claude mcp add --transport http crawlinx https://crawlinx.com/mcp ``` Endpoint `https://crawlinx.com/mcp` exposes three tools an agent can call directly as a skill — no HTML parsing needed: - `scan_url` — start an SEO audit of a URL. - `get_report` — fetch the finished report as structured JSON. - `get_report_markdown` — fetch a compact, LLM-ready Markdown report. Once connected, an agent invokes these tools natively (e.g. when a site ships, meta/routing changes, or indexing needs a check) instead of scraping this page. ### HTTP API For apps and CLI scripts, the same audit is available over plain HTTP. **Start a scan** ``` POST https://crawlinx.com/api/scan Content-Type: application/json {"url":"https://example.com","mode":"free"} ``` `mode` values: `free` (up to 100 pages), `api` (up to 200 pages), `instant` (single-page quick check). Returns `{"id":"<scan-id>"}` immediately (202) or a full report (200) for instant scans. **Get the JSON report** ``` GET https://crawlinx.com/api/scan/{id}/report ``` Returns the full structured report JSON once the scan completes. **Get this Markdown report** ``` GET https://crawlinx.com/r/{id}.md ``` Returns this LLM-ready Markdown document. **List recent public audits** ``` GET https://crawlinx.com/api/reports ``` ### Quick start (curl) ```bash # Start a scan → note the "id" in the JSON response curl -s -X POST https://crawlinx.com/api/scan \ -H 'Content-Type: application/json' \ -d '{"url":"https://example.com","mode":"free"}' # Then, with that id (replace {id}), fetch the Markdown report curl -s https://crawlinx.com/r/{id}.md ``` Full API reference & usage rules: https://crawlinx.com/api