Website Speed Checker
Test up to three pages (desktop or mobile), then compare Core Web Vitals side by side and download the results. A quick tip: enter your homepage and two competitor pages to see how you stack up.
Compare
Enter up to three URLs
Results
Core Web Vitals & Key Metrics
Guide
Interpreting the results (plain English)
Core Web Vitals (the big three)
- LCP — Largest Contentful Paint (target ≤ 2.5s)
- The time for your main content (hero image/headline) to appear. Slow LCP is often caused by large images, render-blocking CSS/JS, or slow hosting.
- Quick wins: compress/resize hero images, lazy-load below-the-fold media, inline critical CSS, defer non-critical JS, use fast hosting/CDN.
- INP — Interaction to Next Paint (target ≤ 200ms)
- How quickly the page reacts after taps/clicks. High INP feels laggy and is usually heavy JavaScript doing too much at once.
- Quick wins: split long JS tasks, remove unused scripts, delay non-essential trackers, prefer lightweight components.
- CLS — Cumulative Layout Shift (target ≤ 0.10)
- How much the layout jumps during load. Shifts cause mis-clicks and frustration.
- Quick wins: reserve width/height for images/embeds, avoid inserting banners above content late, preload key fonts.
Other helpful metrics
- FCP — First Contentful Paint
- When the first bit of content appears. If slow, the browser is likely waiting on CSS/JS or the server.
- Speed Index
- How quickly the page visually fills. Lower is better; affected by image weight, CSS/JS, and network speed.
- TBT — Total Blocking Time
- Time the main thread is blocked by JS. High TBT often correlates with poor INP.
- TTI — Time to Interactive
- When the page becomes fully usable (not just visible). Heavy scripts delay this.
- Server Response Time
- How fast your server responds to the first request. Slow here drags everything else. Check hosting, caching, and database queries.
Tip: test key landing pages regularly. Fix the worst metric first — it’s usually the biggest win.
