Lighthouse Update May Lift PageSpeed Insights Lab Scores

A Google Lighthouse update is changing the way PageSpeed Insights simulates page loads. As a result, some pages may receive higher lab scores even if their content and code have not been changed. The shift is important for marketers who use PageSpeed Insights to monitor performance or report on the results of website work.

The distinction is between a change to a page and a change to the way its load is simulated. With the Lighthouse update, a higher lab score is not necessarily evidence that the page itself has been modified. A page that remains the same can produce a different score after the update because the simulation has changed.

That makes the context of a score especially important when comparing results. A later PageSpeed Insights result can differ from an earlier one without a corresponding edit to the page. Marketers reviewing an increase should therefore avoid treating the score alone as proof that a website change caused the improvement.

The update concerns the simulated page load used for lab scoring. It does not mean that every page will receive a higher score, and a score increase on its own does not establish what changed on a website. The relevant point for reporting is that the measurement process can affect the result independently of page edits.

For teams that track scores over time, the update is a reason to add context to comparisons rather than relying only on the difference between two numbers. When a score rises, the comparison can be read alongside the record of work done on the page and the change to Lighthouse's simulation. This helps distinguish an observed score change from a demonstrated change to the page itself.

What this means for marketers

When reviewing or presenting PageSpeed Insights lab results, note whether the page was changed and whether the results were collected before or after the Lighthouse update. If a score rises without a page edit, describe it as a change in the reported lab score rather than attributing it to website improvements.