Lighthouse + Core Web Vitals for any URL.
Run a Google PageSpeed Insights audit and pull the full Core Web Vitals breakdown — LCP, CLS, INP, FCP, TTFB — for any public URL. Mobile by default.
Need this for 1,000 domains?
The same data is available via the REST API — pay only for what you use, credits never expire.
# Same data, programmatically — first 100 credits free on signup
curl "https://api.rankparse.com/v1/page-performance?url=https://example.com" \
-H "X-API-Key: rp_your_key"About this tool
Page speed is one of the few performance signals Google has publicly confirmed as a ranking factor. The Core Web Vitals — Largest Contentful Paint, Cumulative Layout Shift, and Interaction to Next Paint — are the user-experience metrics Google tracks via the Chrome User Experience Report. A free page speed checker lets you spot-check any URL and see exactly where time is being spent.
This tool runs Google's official PageSpeed Insights API in the background, then surfaces the relevant scores in a clean view. The data is identical to what you'd get from running Lighthouse locally, minus the install.
How it works
Paste a full URL (including https://). The tool runs a Lighthouse audit via PageSpeed Insights and returns three category scores (Performance, Accessibility, SEO) plus the five Core Web Vitals values. CrUX field data is included when available.
Free anonymous use: 5 checks/day. Free account: 25/day. Each upstream PSI call counts against a global daily quota; if the global cap is reached you'll see a quota error and can retry tomorrow. Paid customers have a separate reserved pool that's not affected by free-tool traffic.
Frequently asked questions
- Mobile or desktop?
- Mobile by default — that's how Google ranks pages. Add ?strategy=desktop to the URL to force desktop. The API endpoint accepts the same parameter.
- What's a good score?
- Performance ≥ 90 is strong, 50–89 is OK, below 50 needs work. For Core Web Vitals: LCP < 2.5s, CLS < 0.1, INP < 200ms is the 'Good' threshold.
- Why is the result different each time?
- Lighthouse is sensitive to network and CPU variability — repeat a check 3 times and use the median. The CrUX field data, when present, is more stable because it's aggregated from real Chrome users over the past 28 days.
- Why doesn't this work for localhost?
- PageSpeed Insights crawls from Google's servers, so it can only audit publicly reachable URLs. For local development, run Lighthouse directly via Chrome DevTools.