Free Website Speed Checker
Test your page speed with real Google PageSpeed Insights data. Get a Lighthouse score, Core Web Vitals (LCP, TBT, CLS), and a prioritised fix list for mobile and desktop — free, no account needed.
Enter a URL to analyse
How It Works
Three steps to real Google speed data — no setup, no sign-up.
Enter your URL
Paste any publicly accessible page URL. Choose Mobile (Google's default for indexing) or Desktop analysis.
Google Lighthouse runs
We call Google PageSpeed Insights API to run a real Lighthouse audit — the same tool Google uses. Takes 15–30 seconds.
Fix what matters
Get your performance score (0–100), Core Web Vitals status, and a prioritised list of opportunities with estimated savings.
What We Measure
Seven performance metrics from Google Lighthouse — including all three Core Web Vitals that are confirmed Google ranking signals.
Largest Contentful Paint (LCP)
Core Web VitalTime until the largest visible element finishes rendering. Google's primary loading speed signal. Target: under 2.5 seconds.
Total Blocking Time (TBT)
Core Web VitalTotal time the main thread was blocked and unable to respond to user input. Lighthouse proxy for Interaction to Next Paint (INP). Target: under 200ms.
Cumulative Layout Shift (CLS)
Core Web VitalHow much the page layout unexpectedly shifts while loading. Poor CLS means content jumps around as images and ads load in. Target: under 0.1.
First Contentful Paint (FCP)
PerformanceWhen the browser renders the first visible DOM content — text, image, or canvas. The earliest signal users see that the page is loading.
Speed Index (SI)
PerformanceHow quickly the page content is visually populated. Affected heavily by render-blocking scripts and stylesheets loaded before the page content.
Time to Interactive (TTI)
PerformanceWhen the page is fully interactive — all event handlers registered and the main thread idle for 5 consecutive seconds. Heavy JavaScript delays TTI.
Server Response Time (TTFB)
PerformanceTime to First Byte — how long the server takes to respond to the initial request. The starting point for every other metric. Target: under 800ms.
Why Page Speed Matters for SEO in 2026
Page speed has been a Google ranking signal since 2010, but the stakes increased significantly in 2021 when Google rolled out the Page Experience update, making Core Web Vitals (LCP, INP, CLS) official ranking factors. In 2026, a slow site isn't just a bad user experience — it's a competitive disadvantage in the SERPs.
The numbers are stark: a 1-second delay in page load time reduces conversions by 7% (Akamai). Google's own research found that 53% of mobile visitors abandon a page that takes more than 3 seconds to load. For e-commerce sites, every 100ms of latency costs roughly 1% in revenue.
Speed is also now tied directly to how Google evaluates your content. A technically poor page — even with excellent content and strong backlinks — can be held back by low Core Web Vitals scores in competitive niches. Passing all three Core Web Vitals thresholds is the minimum bar for competing on page one in 2026.
Unlike many ranking factors, page speed is entirely within your control. The most common fixes — compressing images, deferring non-critical JavaScript, enabling text compression, reducing server response time with caching — can move a site from a score of 40 to 80+ with engineering effort over days, not months. The Opportunities section in your speed report shows exactly where the biggest gains are, ranked by estimated impact.
7%
conversion drop per 1s delay
53%
abandon if load > 3 seconds
100%
free, powered by Google
Mobile vs Desktop: Why Both Matter
Lighthouse uses different simulated network and CPU conditions for each strategy.
Mobile
Test first — Google's default
- Simulates slow 4G network (40Mbps throttled)
- CPU throttled 4× slower than desktop
- Used by Google for mobile-first indexing
- Scores below 90 are very common — most sites score 40–70
Desktop
Faster network & CPU conditions
- No network throttling (fast broadband simulated)
- No CPU throttling — full processing speed
- Scores are typically 15–30 points higher than mobile
- Useful for diagnosing desktop-specific JS issues
Frequently Asked Questions
Everything about website speed testing, Core Web Vitals, and Lighthouse scores.
Is this website speed checker free?
Yes — 100% free, no sign-up, no usage limits. Just enter a URL and get real Google PageSpeed Insights data instantly.
What data source does this tool use?
We use the Google PageSpeed Insights API v5, which runs a real Lighthouse audit. This is exactly the same data source as Google's own PageSpeed Insights tool at pagespeed.web.dev. The results are identical.
Why does the analysis take 15–30 seconds?
Google's Lighthouse runs a full simulated browser session — loading your page from scratch, measuring paint timings, tracking layout shifts, and profiling JavaScript execution. This takes real time and cannot be shortcut. The wait is worth it: you get genuine performance data, not estimates.
What are Core Web Vitals and why do they matter for SEO?
Core Web Vitals are three Google-defined metrics that measure user experience: LCP (loading speed), INP/TBT (interactivity), and CLS (visual stability). Since Google's Page Experience update, these are confirmed ranking signals. Pages that pass Core Web Vitals thresholds can achieve better rankings in competitive niches, all else being equal.
What is a good PageSpeed Insights score?
Scores of 90–100 are considered Fast (Grade A). Scores of 50–89 need improvement (B/C). Scores below 50 are Slow (D/F). For competitive keywords, aim for 90+ on mobile. Most sites score 50–80 on mobile due to unoptimised images and render-blocking JavaScript.
Should I test mobile or desktop?
Test mobile first. Google uses mobile-first indexing for all websites — meaning it crawls and ranks your site based on the mobile experience. Mobile scores are almost always lower than desktop scores due to the slower simulated network conditions Lighthouse uses (slow 4G). Fix mobile first; desktop improvements usually follow.
What is Largest Contentful Paint (LCP) and how do I fix it?
LCP measures how long until the largest visible element — usually a hero image, heading, or banner — finishes loading. Common fixes: compress and resize images, use next-gen formats (WebP/AVIF), add fetchpriority='high' to your hero image, preload critical assets, and ensure your server responds under 800ms (TTFB). A good LCP score is under 2.5 seconds.
What is Cumulative Layout Shift (CLS) and how do I fix it?
CLS measures how much the page layout shifts unexpectedly while loading — content jumping around as images, ads, or web fonts load in. Fix it by: always setting explicit width and height on images and videos, reserving space for ads and embeds before they load, using font-display: optional or swap for web fonts, and avoiding injecting content above existing content dynamically.
Can I audit pages behind a login?
No. The tool uses Google's API, which fetches your page as an unauthenticated visitor — the same way Googlebot does. Only publicly accessible pages can be tested. For authenticated pages, use Chrome DevTools Lighthouse locally.
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