Web VitalsLCP, INP, CLS & more Techniques62 performance techniques SnippetsReady-to-use code patterns AnswersCommon questions answered ImpactsReal-world impact data BottlenecksRoot causes & patterns

Knowledge

Web Vitals Techniques Snippets Answers Impacts Bottlenecks

Main Thread Workload

Long tasks block the main thread. Click and feel the delay.

CLS: –
LCP: –
INP: –
FCP: –
TTFB: –

LCP image used for a main-thread workload test

300 ms workload

Test builder

Run timemsDelay JS fix

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LCP · INP · CLS — fixed at the root.

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