Measure page quality - web.dev

... Insights](https://developers.google.com/speed/pagespeed/insights/) tool. ... When you measure your site, web.dev uses Lighthouse, an open-source, ... SkiptocontentOpenmenuLearnMeasureBlogCasestudiesAboutCloseRuntestsonyoursiteEnteryoursite'sURLtoseehowwellitperformsacrossallaudits.LookatwhatmattersSeeyoursite'sperformanceacrosstheareasyoucareabout.GettipsforimprovingEachtestcomeswithhelpfulstepstoimproveyoursite'sresults.HowyoursiteismeasuredWhenyoumeasureyoursite,web.devusesLighthouse,anopen-source,automatedtoolforimprovingthequalityofwebpages.Lighthousewillaudityoursiteinthefollowingcategories:Whatisthedatasourcepoweringtheweb.dev/measuretool?web.dev/measureusesLighthousedatafromthePageSpeedInsightsAPI.LearnmoreaboutPageSpeedInsightsintheofficialFAQsHowdoesweb.dev/measuredifferfromPageSpeedInsights?web.dev/measuremeasurestheoverallqualityofawebpageinalabenvironment(usingLighthouse).ItgivesinsightsaboutmultiplequalitycategoriesfromLighthouse,includingPerformance,AccessibilityandSEO.PageSpeedInsights(PSI)isperformancefocused,usingbothlab(Lighthouse)andfield(ChromeUXReport)datatoprovideasummaryofperformance.Furthermore,PSIprovidesoriginlevelinsightsinthefield,whereasweb.dev/measureisintendedtodeep-diveintoasingleURLinthelab.UsePSIwhenyouwanttomeasureandoptimizeyourCoreWebVitals,anduseweb.dev/measurewhenoptimizingabroadersetofqualitysignalsaboutapage.