Lighthouse Update May Raise PageSpeed Insights Scores

A Lighthouse update is changing the way PageSpeed Insights simulates page loads, and the change may result in higher lab scores for some pages. According to Search Engine Journal, a score can rise even if the page itself has not been altered.

The distinction matters when interpreting a new result against an earlier one. A higher score might appear to signal that a page has been improved, but the Lighthouse update introduces another possible explanation: the simulated load is being assessed differently. The score change alone does not establish that someone made changes to the page.

The effect is a possibility rather than a guarantee for every page. An unchanged page may receive a higher lab score following the update, but the information available does not specify which pages will see a change or how large any increase might be. It also does not establish that the update is responsible for every score increase observed after it.

The reported change concerns the simulation used for lab scores. Those scores should therefore be read in the context of the tool and its updates, rather than treated as a record of page changes on their own. A comparison between results can show that a score has moved, but it cannot by itself explain whether the page, the simulation or another factor accounts for the difference.

What this means for marketers

When reviewing PageSpeed Insights results, marketers should avoid assuming that a higher lab score necessarily reflects work completed on a page. Compare the timing of the result with the Lighthouse update and check whether the page was changed before attributing the increase to an optimization. Where the cause is unclear, describe the result as a score change rather than as proof that the page itself has improved.