Why it matters
Third-party scripts (analytics, chat, tag managers, embeds) are outside your control and are a leading cause of long tasks and poor INP.
How to fix it
Remove unused tags, load the rest after interaction or idle (next/script lazyOnload), self-host critical ones, and use facades for embeds.
More performance rules
void perf reports 25 rules in this category. Core Web Vitals and bytes: LCP, CLS, TBT, TTFB, JavaScript, CSS, fonts, images, caching and compression, measured as the median of several runs on a throttled mobile and a desktop profile.
images-missing-dimensionsImages without width/height or aspect-ratiorender-blockingRender-blocking resources delay first paintno-text-compressionText resources are served uncompressedcache-headersHashed static assets are not cached long-termdom-sizeDOM is very largebfcache-blockedPage is not eligible for the back/forward cachelighthouse-score-lowLighthouse performance score is lowlighthouse-auditLighthouse flagged an opportunity