How we measure
How this differs from PageSpeed
Two scores, two different questions
PageSpeed Insights and LLM Site Check both give you a score out of 100. They are not measuring the same thing, and a good score from one does not mean the other agrees.
Where we agree
We checked our findings against PageSpeed on the same live pages. Where the two tools cover the same ground, such as titles, meta descriptions and structured data, we do not contradict each other. We go further than PageSpeed does here: it only checks whether a title or description exists, not whether the length is well chosen for how search results display it. We check both.
What PageSpeed cannot see
Some of what we flag is invisible to PageSpeed by design, not by mistake.
Keyboard focus
PageSpeed’s automated audit does not simulate a person tabbing through a page. We do. A control with no visible focus ring is a real barrier for keyboard and screen reader users, and it will not show up in a PageSpeed report.
A true mobile width
PageSpeed emulates a phone at roughly 412 pixels wide. We test at 320, the width Apple and Google’s own accessibility guidelines use as the baseline. Content that overflows only becomes visible at the narrower width.
One page against your whole sitemap
PageSpeed audits the single URL you give it. We crawl up to 30 pages from your sitemap, because a defect that lives in a template appears on every page it is used on, and a homepage-only scan will never find it.
Every number is measured
Nothing in an LLM Site Check report is a guess. Every check that produces a finding has been tested to prove it two ways: that it fires on a genuine problem, and that it stays quiet on correct markup. Where a check cannot establish something reliably, it says nothing rather than inventing an answer.
What this means for you
A clean PageSpeed report and a poor score here are not a contradiction. It usually means your site passes the checks a generic tool can automate, and fails the ones that require actually reading the page the way a person, or the browser itself, would.