Test any URL with Google PageSpeed Insights. Get your performance score, Core Web Vitals, actionable opportunities, and field data from real users. No API key. No signup.
Test Your Page Speed
Enter a URL to test
Paste any public URL above to get Google PageSpeed scores, Core Web Vitals, and actionable improvements.
Core Web Vitals Explained
Google measures page experience using six metrics. Three are Core Web Vitals used in ranking. Here is what each measures, the thresholds Google uses, and the most common cause of failure.
| Metric | Full Name | Good | Needs Work | Poor | Ranking Signal | Common Cause of Failure |
|---|---|---|---|---|---|---|
| LCP | Largest Contentful Paint | < 2.5 s | 2.5 to 4 s | > 4 s | Core Web Vital | Unoptimised hero image, slow server, render-blocking CSS |
| INP | Interaction to Next Paint | < 200 ms | 200 to 500 ms | > 500 ms | Core Web Vital | Heavy JavaScript blocking the main thread during interactions |
| CLS | Cumulative Layout Shift | < 0.1 | 0.1 to 0.25 | > 0.25 | Core Web Vital | Images without width/height, late-loading ads, web fonts |
| FCP | First Contentful Paint | < 1.8 s | 1.8 to 3 s | > 3 s | Lab diagnostic | Render-blocking resources, slow server response time |
| TTFB | Time to First Byte | < 800 ms | 800 to 1800 ms | > 1800 ms | Lab diagnostic | Slow server, no caching, distant origin, no CDN |
| TBT | Total Blocking Time | < 200 ms | 200 to 600 ms | > 600 ms | Lab diagnostic | Large JS bundles, third-party scripts (ads, chat, analytics) |
Field Data vs Lab Data
This tool shows both data sources when available. Field data comes from the Chrome User Experience Report (CrUX), reflecting real user experiences over the past 28 days. Lab data comes from Lighthouse running in a controlled simulation. Google uses field data for Core Web Vitals ranking decisions, not lab scores.
Pages without enough real traffic in CrUX will show only lab data. A page must receive sufficient visits from Chrome users to appear in the CrUX dataset.
Performance Score Calculation
The overall performance score is a weighted average of five lab metrics: TBT (30%), LCP (25%), CLS (15%), FCP (15%), Speed Index (10%). The score is not a direct ranking signal. It is a summary diagnostic to help you prioritise improvements.
| Score range | Label | Google colour | Action priority |
|---|---|---|---|
| 90 to 100 | Good | Green | Maintain. Monitor for regressions. |
| 50 to 89 | Needs Improvement | Orange | Work through Opportunities in order of estimated savings. |
| 0 to 49 | Poor | Red | Treat as a ranking risk. Fix critical issues first. |
How This Tool Compares
Most free PageSpeed checkers show only the score and a list of issues with no context, no field data, and no export. Here is what sets this tool apart.
| Feature | SmallSEOTools / GTmetrix free / competitors | This tool |
|---|---|---|
| Data source | Some use private crawlers, not Google | Official Google PSI API (same data as PageSpeed Insights) |
| Field data (real users) | Lab data only | CrUX field data shown separately from lab data |
| Device testing | One device at a time | Desktop + mobile tested simultaneously |
| Opportunities detail | List of issues, no explanations | Expandable items with estimated ms savings + fix guidance |
| INP metric | FID (deprecated since March 2024) | INP (current Core Web Vital since March 2024) |
| Bulk URL testing | One URL at a time | Unlimited URLs, table output with all scores |
| Score history | No history within session | Visual bar chart of all tests in session |
| Desktop vs mobile compare | Separate views | Side-by-side comparison tab |
| Passing audits | Hidden or not shown | Full list so you know what is already good |
| Export | Screenshot only or paid | JSON and CSV download, shareable URL |
| Raw API response | No | Full raw JSON tab for developers |
PageSpeed Fix Priority Guide
Fix opportunities in order of estimated time savings shown in the Opportunities tab. This table shows the highest-impact fixes across most websites, ranked by typical improvement.
| Fix | Typical saving | Metrics improved | Difficulty |
|---|---|---|---|
| Convert images to WebP or AVIF | 1 to 4 s | LCP, FCP | Low |
| Add image width and height attributes | CLS fix | CLS | Low |
| Defer offscreen images (lazy load) | 0.5 to 2 s | LCP, FCP, TBT | Low |
| Eliminate render-blocking resources | 0.5 to 3 s | FCP, LCP, TBT | Medium |
| Reduce unused JavaScript | 0.5 to 2 s | TBT, INP, LCP | Medium |
| Reduce unused CSS | 0.3 to 1 s | FCP, LCP | Medium |
| Enable text compression (Brotli / gzip) | 0.5 to 1.5 s | FCP, TTFB | Low |
| Serve static assets via CDN | 0.3 to 2 s | TTFB, LCP, FCP | Medium |
| Reduce server response time (TTFB) | 0.5 to 3 s | TTFB, FCP, LCP | High |
| Preload critical fonts | 0.2 to 1 s + CLS fix | CLS, FCP | Low |
Frequently Asked Questions
Google classifies scores 90 to 100 as Good (green), 50 to 89 as Needs Improvement (orange), and 0 to 49 as Poor (red). A score above 90 on both mobile and desktop means your page passes Core Web Vitals thresholds and is unlikely to receive a ranking penalty from Google's page experience signal.
Lab data (Lighthouse) is collected in a controlled environment using a simulated device and network. Field data (CrUX) is collected from real Chrome users visiting your site over the past 28 days. Google uses field data for Core Web Vitals ranking decisions. If your lab score is high but field data is poor, real users on slower connections are experiencing worse performance than the lab suggests.
LCP (Largest Contentful Paint) measures how long it takes for the largest image or text block visible in the viewport to fully render. Google's threshold for Good LCP is under 2.5 seconds. LCP is a Core Web Vital and a confirmed Google ranking factor. Slow LCP typically means your hero image, above-the-fold text, or server response is too slow.
Google replaced FID (First Input Delay) with INP (Interaction to Next Paint) as a Core Web Vital in March 2024. INP measures the latency of all interactions on a page, not just the first one. A Good INP score is under 200 milliseconds. INP is a more comprehensive measure of a page's responsiveness throughout the entire visit.
Google Lighthouse simulates a mid-range Android device with a throttled 4G connection for mobile tests. Desktop tests use no network throttling and assume a faster CPU. A mobile score of 50 and a desktop score of 90 is common and expected. Prioritise mobile fixes because Google uses mobile-first indexing, meaning your mobile page performance affects your rankings.
The most impactful fixes in order of typical savings are: serve images in WebP or AVIF format, add proper image dimensions to prevent layout shift, defer render-blocking JavaScript and CSS, enable text compression (Brotli or gzip), use a CDN, and reduce server response time. The Opportunities tab in this tool shows each issue with an estimated time saving specific to your page.
Google's page experience ranking signal uses Core Web Vitals field data (LCP, INP, CLS), not the overall Lighthouse score number. A page with Good field data on all three Core Web Vitals receives a small ranking boost. The Lighthouse performance score is a useful diagnostic tool but Google does not use the score itself as a direct ranking input.