Website Speed Test, Full Lighthouse Audit in One Click
Enter any URL and get a complete Lighthouse report, Performance, SEO, Accessibility, and Best Practices scores, Core Web Vitals like LCP and CLS, and the top five fixes that will improve your speed the most.
Core Web Vitals Thresholds You Need to Hit
Google evaluates page experience through three Core Web Vitals, each with a clear passing threshold measured at the 75th percentile of real users. Largest Contentful Paint (LCP) measures loading and should complete within 2.5 seconds, anything over 4 seconds is rated poor. Cumulative Layout Shift (CLS) measures visual stability and should stay below 0.1, so images without dimensions, late-loading ads, and injected banners are the usual culprits when it fails. Interaction to Next Paint (INP) measures responsiveness and should stay under 200 milliseconds, which is why this report also surfaces Total Blocking Time, the lab metric that best predicts INP problems caused by heavy JavaScript.
The Lighthouse performance score in this tool blends these signals with First Contentful Paint and Speed Index into a single 0 to 100 number. A score of 90 or above is good, 50 to 89 needs improvement, and below 50 is poor. Rather than chasing the composite score, work through the individual failing metrics: compress and preload your LCP image, reserve space for every embed to fix CLS, and split or defer JavaScript bundles to bring blocking time down. Each fix moves both the lab score and the field data Google actually ranks with.
Why Page Speed Now Shapes AI Search Visibility Too
Speed has always influenced crawling, Googlebot allocates crawl budget partly on how quickly your server responds, so a slow site simply gets fetched less often and indexed more slowly. In the AI search era that dynamic intensifies. Crawlers feeding AI Overviews, ChatGPT, Perplexity, and other answer engines operate on tight fetch timeouts and enormous queues. Pages that respond slowly or require heavy rendering are more likely to be skipped, truncated, or represented by stale copies, which means your content never makes it into the corpus these systems cite from.
Fast pages also tend to be architecturally simple pages, server-rendered HTML, minimal blocking scripts, and content visible without JavaScript execution. Those same properties make your content easy for AI crawlers to parse and quote accurately. If your goal is to be cited in AI answers, treat the performance work surfaced by this audit as retrieval optimization, not just user experience polish: every second you shave off load time increases the odds that both classic search and answer engines see, store, and surface your best content.