Website speed test: how fast is your website?
Enter any URL and get a performance report with Core Web Vitals and prioritized fixes in seconds.
Why website speed matters
Website speed directly affects how users experience your site and how search engines rank it. A slow site frustrates visitors, increases bounce rates, and costs you conversions. Research consistently shows that every additional second of load time reduces conversions by 4.4% on average.
Google uses Core Web Vitals - Largest Contentful Paint (LCP), Cumulative Layout Shift (CLS), and Interaction to Next Paint (INP) - as ranking signals. Meeting the recommended thresholds gives your pages a measurable advantage in search results.
What affects website loading speed?
Images & media
Unoptimized images are the #1 cause of slow pages. Using modern formats (WebP, AVIF), lazy loading, and proper sizing can cut load times dramatically.
JavaScript & CSS
Render-blocking scripts delay page display. Minimizing, deferring, and code-splitting JavaScript reduces Total Blocking Time and improves interactivity.
Server response time
Slow Time to First Byte (TTFB) delays everything else. A CDN, server-side caching, and efficient backend code reduce TTFB significantly.
Third-party scripts
Analytics, chat widgets, ad tags, and social embeds each add network requests and JavaScript. Audit and lazy-load non-essential third-party code.
Core Web Vitals thresholds (2026)
| Metric | Good | Needs improvement | Poor |
|---|---|---|---|
| LCP (Largest Contentful Paint) | ≤ 2.5s | 2.5s – 4.0s | > 4.0s |
| INP (Interaction to Next Paint) | ≤ 200ms | 200ms – 500ms | > 500ms |
| CLS (Cumulative Layout Shift) | ≤ 0.1 | 0.1 – 0.25 | > 0.25 |
Frequently asked questions
- How does this website speed test work?
- This tool uses the Google PageSpeed Insights API, which runs a full Lighthouse audit on your URL. It measures real-world performance metrics including Core Web Vitals, then returns scored results with prioritized optimization recommendations.
- What is a good website speed score?
- A performance score of 90–100 is considered good, 50–89 needs improvement, and 0–49 is poor. For Core Web Vitals, Google recommends LCP under 2.5 seconds, CLS under 0.1, and INP under 200 milliseconds.
- Why is my mobile score lower than desktop?
- Mobile scores are typically lower because Lighthouse simulates a mid-tier mobile device on a slower network connection. This reflects real-world conditions for most mobile users. Desktop tests assume a faster device and network.
- How can I improve my website speed?
- The most impactful improvements are: optimize images with modern formats (WebP, AVIF), minimize and defer JavaScript, use a CDN, enable browser caching, and reduce server response time. This tool shows your specific opportunities sorted by impact.
- Does website speed affect SEO rankings?
- Yes. Google uses Core Web Vitals as a ranking signal. Sites meeting the recommended thresholds get a ranking boost. Beyond SEO, faster sites have lower bounce rates and higher conversion rates - a 1-second delay can reduce conversions by up to 7%.
- What's the difference between lab data and field data?
- Lab data (like this Lighthouse test) measures performance in a controlled, simulated environment - repeatable and ideal for debugging. Field data (Chrome UX Report) reflects what real users experienced over the last 28 days. Google ranks on field data, so use lab tests to find and fix issues, then confirm in real-user data.
- What is TTFB and why does it matter?
- Time to First Byte is how long the server takes to send the first byte of the page. A slow TTFB (over about 800ms) delays everything that follows and drags down LCP. It's usually fixed with faster hosting, server-side caching, and a CDN.
- How often should I test my website speed?
- Test after any significant change - a new theme, plugins, large images, or added third-party scripts - and at least monthly. Performance regresses quietly as content and tags accumulate, so periodic checks catch slowdowns early.
- Is this website speed test free?
- Yes - completely free with no signup. Enter any URL and get a scored Core Web Vitals report with prioritized fixes in seconds.
Why website speed matters for your business
Page speed is a confirmed Google ranking factor and directly impacts user behavior. Every 1-second increase in load time increases bounce rate by approximately 32% (Google). For e-commerce sites, a 100ms improvement in load time can increase conversion rates by 8.4% (Deloitte).
Understanding your speed test results
Score 90–100 (Green): Excellent. Your site loads fast and provides a good user experience. Focus on maintaining this performance as you add features.
Score 50–89 (Orange): Needs improvement. Users are likely experiencing some delay. Focus on the specific recommendations in your report - image optimization and render-blocking resources are the most common fixes.
Score 0–49 (Red): Poor. Your site is losing visitors and rankings due to slow loading. Prioritize the top 3 recommendations immediately.
The 5 most common speed issues (and how to fix them)
- Unoptimized images - Serve images in WebP/AVIF format, compress to 80% quality, and use responsive sizes. This alone fixes 40% of speed issues.
- Render-blocking JavaScript - Defer non-critical scripts and move them to the bottom of the page. Use
asyncordeferattributes. - No browser caching - Set cache headers for static assets (images, CSS, JS) to at least 1 year for versioned files.
- Cheap shared hosting - Upgrading from $5/month shared hosting to $20–50/month managed hosting often cuts load time in half.
- Too many HTTP requests - Combine CSS files, reduce third-party scripts, and lazy-load below-fold content.
Mobile vs desktop speed
Mobile speed matters more than desktop for most businesses. Over 60% of web traffic is mobile, and Google uses mobile-first indexing. A site that scores 90 on desktop but 45 on mobile is effectively a slow site in Google's eyes. Always test and optimize for mobile first.
For a complete technical SEO audit including speed optimization, read our Technical SEO Checklist. For broader website performance strategy, see our Website Development Guide.
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