Run a real PageSpeed Insights and Lighthouse analysis for any public webpage. Enter a URL below, choose Mobile or Desktop, and review the performance score and metrics returned by Google’s testing service.
Free Website Speed Test
Use this free page speed test to check loading performance, rendering, responsiveness, and layout stability. The report is generated only after you click the test button; it does not use sample or estimated scores.
Lighthouse Performance Score
Website tested:
Test type:
Core and Lab Metrics
Lighthouse Categories
Performance Recommendations
API key notice: This browser-based tool uses a client-side Google API key, so visitors can inspect it. The key should be restricted in Google Cloud to the PageSpeed Insights API and appropriate HTTP referrers for the PerformanceX AI domain. Rotate the key if it has been exposed or compromised. It is not treated as a secret in this client-side implementation.
How to Use the Free Website Speed Test
Testing a page takes only a few steps. First, enter the full URL, including https:// or http://. Next, select Mobile or Desktop, then click Test Page Speed. Wait for the PageSpeed Insights analysis to finish and review the returned score, metrics, categories, and recommendations. After making improvements, run the test again and compare the results.
What This Website Speed Test Measures
This free website performance test uses the PageSpeed Insights API to request Lighthouse data for the webpage you submit. Lighthouse evaluates loading behavior, rendering, main-thread activity, layout stability, interaction responsiveness where supported, resource efficiency, and opportunities that may help improve performance. The API can also return Accessibility, Best Practices, and SEO category scores when they are available.
A lab test is a controlled analysis rather than a complete census of real visitors. Device capabilities, network conditions, browser state, location, server load, and page content can all affect the result. For real-user monitoring, combine lab testing with field data such as the Core Web Vitals information available in Search Console and other monitoring systems.
Understanding Your PageSpeed Score
The Performance score shown above is read directly from lighthouseResult.categories.performance.score and converted to a 0–100 value. Lighthouse describes the ranges as follows:
| Score | Classification | Interpretation |
|---|---|---|
| 90–100 | Good | The Lighthouse performance result is in the green range. |
| 50–89 | Needs Improvement | The page has measurable opportunities for improvement. |
| 0–49 | Poor | The page has substantial performance issues under this test configuration. |
This is a Lighthouse performance score—not a Google ranking score, guaranteed SEO score, guaranteed conversion score, or promise of faster performance for every real user. A score of 100 is also not a practical requirement for every page; prioritize a reliable user experience and the issues that matter most to your audience.
Understanding LCP, INP, and CLS
Largest Contentful Paint (LCP) measures when the largest visible content element has rendered. As a general user-experience target, Google recommends an LCP of 2.5 seconds or less at the 75th percentile.
Interaction to Next Paint (INP) measures responsiveness to user interactions. A good target is 200 milliseconds or less at the 75th percentile. Lighthouse lab runs do not have real user input, so INP may be absent from a lab result; Total Blocking Time is commonly used as a lab signal related to responsiveness.
Cumulative Layout Shift (CLS) measures unexpected movement of visible page content. A good target is a CLS of 0.1 or less at the 75th percentile. Reserve space for images and ads, avoid injecting content above existing content, and manage font loading carefully to reduce shifts.
For current definitions and thresholds, see Google’s Core Web Vitals documentation.
Understanding FCP, TBT, Speed Index, and TTFB
First Contentful Paint (FCP) is the time until the browser renders the first piece of page content. Total Blocking Time (TBT) is a Lighthouse lab metric related to how long long-running main-thread tasks can delay responsiveness. Speed Index describes how quickly visible content is populated during loading. Time to First Byte (TTFB) is the time taken to receive the first byte of the response from the server.
The tool displays a metric only when the API returns a suitable audit value. Missing values remain absent rather than being replaced with invented measurements.
Mobile vs. Desktop Website Speed
Mobile and desktop tests can produce different results because Lighthouse uses different device and network assumptions. Mobile conditions often expose the effect of slower CPU processing, JavaScript execution, image payloads, CSS complexity, and server response time. Desktop testing can help identify how the page behaves on a larger and typically more capable device, but it should not replace mobile testing.
Run both strategies when diagnosing an issue. If mobile is much slower, inspect JavaScript execution, responsive images, render-blocking resources, layout work, and third-party scripts. If both are slow, investigate server response time, asset delivery, caching, redirects, and page weight.
Why Website Speed Test Results Change
A single run is not an absolute representation of website performance. Results can change because of server load, network routing, cache conditions, dynamic content, advertisements, third-party scripts, recent page changes, backend response time, and the test environment itself. Lighthouse’s documentation recommends thinking about performance as a distribution of results rather than relying on one number.
For a useful trend, test the same URL and strategy several times under comparable conditions, record the date and major changes, and look for repeated patterns. Field data is especially valuable because it captures the experience of actual visitors.
Common Causes of Slow Websites
Slow pages frequently combine several small problems rather than one isolated defect. Large or incorrectly sized images increase transfer and decoding work. Excessive JavaScript can delay the main thread. Unused CSS, multiple redirects, slow fonts, weak caching, and too many third-party requests add additional work before visitors can read or interact with the page.
Content management systems such as WordPress and Blogger can also accumulate plugins, widgets, themes, tracking tags, and advertising components. Review each addition against its value, and remove resources that do not support a clear user or business goal.
How to Improve Website Loading Speed
Start with the opportunities returned for the specific page, then apply changes in priority order. Optimize images and serve appropriately sized files in modern formats when suitable. Reduce unnecessary JavaScript and unused CSS, defer non-critical work, and minimize third-party scripts. Improve server response time, use browser and server caching appropriately, reduce redirects, optimize font delivery, and reserve layout space for images, embeds, and advertising.
Prioritize the content visitors need first. A page that renders its main content quickly can feel responsive even while lower-priority resources continue loading. After each significant change, use this free website speed checker again and monitor Core Web Vitals in field data. No optimization list can guarantee a particular score because results depend on the page, server, device, and test conditions.
Website Speed Testing Methods Compared
| Method | Main purpose | Best for |
|---|---|---|
| PageSpeed Insights | Lighthouse-based webpage analysis with available field information | General website performance analysis |
| Browser Performance API | Measurements from the current browser session | Quick technical checks in a live page |
| WebPageTest | Controlled testing with advanced diagnostics | Detailed investigations and waterfall analysis |
| Real User Monitoring | Performance measurements from actual visitors | Production monitoring and regression detection |
No method is universally best. A free page speed test is a useful starting point, while deeper diagnostics and real-user data provide additional context.
Website Speed vs. Internet Speed
A website speed test measures how a webpage and its resources load and render. An internet speed test measures the connection’s download and upload capacity, latency, and related network characteristics. They answer different questions. If you want to understand a slow page, test the page URL itself rather than testing the speed of your internet connection.
Frequently Asked Questions
What is a free website speed test?
A free website speed test is an online tool that analyzes a webpage’s loading and performance characteristics without charging the user. This tool requests real PageSpeed Insights and Lighthouse results for the URL you submit.
How can I test my website speed for free?
Enter your full webpage URL in the tool, choose Mobile or Desktop, and select Test Page Speed. Review the returned Lighthouse score and metrics, make improvements, and retest.
How do I test web page loading speed?
Use a page speed checker such as the tool on this page and test the exact URL you want to diagnose. Test important templates separately because a homepage result may not represent a product, article, category, or checkout page.
What is a good website speed score?
Lighthouse classifies 90–100 as Good, 50–89 as Needs Improvement, and 0–49 as Poor. Treat the score as one diagnostic signal and also review the underlying metrics and real-user experience.
Why is my website slow?
Common causes include oversized images, excessive JavaScript, unused CSS, slow server response, redirects, unoptimized fonts, poor caching, and third-party scripts. The recommendations in the returned report can help identify page-specific opportunities.
Why is my mobile score different from desktop?
The two strategies use different device and network assumptions. Mobile testing can reveal CPU, transfer-size, rendering, and JavaScript issues that may be less visible in a desktop run.
What is a good LCP?
Google recommends aiming for an LCP of 2.5 seconds or less at the 75th percentile for a good user experience.
What does INP mean?
INP means Interaction to Next Paint. It measures how promptly a page responds to user interactions. A good target is 200 milliseconds or less at the 75th percentile.
What does CLS mean?
CLS means Cumulative Layout Shift. It measures unexpected movement of visible content. A CLS of 0.1 or less is the recommended good target at the 75th percentile.
Does PageSpeed Insights affect Google rankings?
Running a PageSpeed Insights test does not itself change a ranking. Core Web Vitals and other page-experience signals are considered among many factors, but a Lighthouse score is not a guaranteed ranking result.
How often should I test my website speed?
Test after major design, content, plugin, theme, server, or advertising changes, and establish a recurring monitoring routine for important pages. The right frequency depends on how often your site changes and how important performance is to your business.
Conclusion
A free website speed test gives you a practical way to begin diagnosing page performance. The most useful workflow is to measure the exact page, compare mobile and desktop results, understand the metrics, apply targeted improvements, and validate the change with another test. Use Lighthouse lab data for diagnosis and real-user data for the experience your audience actually receives.
Suggested Alt Text: Free website speed test showing webpage performance metrics
References
[1] Google Developers: Get Started with the PageSpeed Insights API
[2] Google Developers: PageSpeed Insights API runPagespeed method
[3] Google Search Central: Understanding Core Web Vitals and Google search results
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