Lab run
One simulated Lighthouse visit. Useful for diagnosis and repeatable comparisons, but naturally variable.
Mobile + desktop · Lighthouse snapshot
Free website page speed test.
Compare one public page under mobile and desktop test conditions. See the lab metrics, available real-user Core Web Vitals and the work most likely to improve the next run.
Test a pageTest one public page
Which page should Google Lighthouse run?
Use a homepage or a specific landing page. Mobile and desktop runs start together and can take up to two minutes.
Google's PageSpeed Insights service receives the public address and runs Lighthouse. Recent results may be reused briefly so a repeat check can finish faster.
Three different kinds of evidence
A score is a clue, not a promise.
Use the snapshot to choose what to investigate. Confirm improvements with repeated tests and, where available, real-user monitoring.
Field data
Aggregated Chrome user experience at the 75th percentile when Google has enough eligible observations.
Business outcome
Speed can support user experience, but this test cannot promise rankings, accessibility, traffic or conversions.
Current Core Web Vitals targets
What “good” field performance means.
The recommended target is to meet all three thresholds at the 75th percentile, separately for mobile and desktop users.
Read Google's Web Vitals guidanceLCP≤ 2.5 sLoading
INP≤ 200 msResponsiveness
CLS≤ 0.10Visual stability
Page speed questions
Know what this snapshot can tell you.
What does the Lighthouse performance score mean?
It is a weighted lab score produced under Lighthouse test conditions. It is useful for diagnosis, but it can vary and is not the same as real-user Core Web Vitals data.
Why are mobile and desktop results different?
The two strategies use different simulated device and network conditions. Mobile often exposes constraints that are less visible in a desktop run.
Why is field data unavailable for my page?
Chrome UX Report data appears only when a page or origin has enough eligible traffic. A new or lower-traffic page may have no field data even though its lab test works normally.
Does a high score guarantee better search rankings?
No. Performance and page experience can matter, but one Lighthouse result cannot guarantee rankings, traffic, accessibility or conversions.
Why can the score change between tests?
Page content, third-party scripts, server response, test infrastructure and network conditions can all vary. Compare several runs and look for a pattern.