SEO health is a 0–100 score Crawlinx computes from 157 technical checks run on every crawled page — indexability, titles and meta descriptions, canonical and hreflang correctness, internal linking, redirects, broken links and Core Web Vitals signals. A site scores high only when the whole crawl is clean, so a single median hides a spread worth reading below.
Across 148 Squarespace sites the median SEO health is 51, with the middle half falling between 40 (25th percentile) and 63 (75th percentile). The full range runs from 30 to 72. That wide gap says the segment is not uniformly good or bad — platform defaults set a baseline, but individual configuration decides where a site lands. Compare your own score against the 75th percentile, not the median, to see what a well-run peer looks like.
Because these sites share the Squarespace platform, they inherit the same defaults — its templating, URL structure, sitemap and meta handling — which is why they cluster. The remaining variance is down to theme, plugins and how each team configured them, so the most common issues below are the ones Squarespace does not solve out of the box and every Squarespace site owner should verify.
The single most common problem here is “Missing Open Graph tags”, present on 100% of the sample, followed by “No llms.txt for AI agents” and “Missing recommended security headers”. The full ranking is in the table above — fix the top of that list first, since it is the fault most likely to be dragging this segment's median down.