A free page speed test for any URL
Paste any URL and we run it through Google's PageSpeed Insights API on mobile, the same lab test you get at pagespeed.web.dev. It loads the page on a simulated mid-range phone over a throttled connection. The main figure is the Speed Index (how quickly the page visibly fills in), with the Lighthouse performance score out of 100 underneath. If Speed Index isn't available we show Largest Contentful Paint instead. Because the numbers come from Google's own tool, anyone can verify them.
What the number does and doesn't tell you
This is a lab result from a single run, so it can move a little between checks even when nothing changed. It is not the same as Core Web Vitals, which Google measures from real Chrome users (the CrUX dataset) and which feed its page-experience signals. A lab test is the right tool for catching regressions before your visitors do; for field data, look at the Core Web Vitals report in Search Console or the field-data section of PageSpeed Insights.
Does page speed affect Google rankings?
Somewhat. Core Web Vitals are part of Google's page-experience signals, but Google is clear that it still ranks the most relevant content first, even when its page experience is weaker. In practice speed works more like a tie-breaker between comparable pages. The stronger reason to fix a slow page is that visitors feel it.
How to run a fair website speed test
Lab tests vary from run to run, because network conditions and server response times change. To test website speed fairly, test the exact URL your visitors land on (with or without www, on https), run the test two or three times and look at the typical result rather than the best one, and change one thing at a time between tests. If your page sits behind a CDN, the first test after a deploy can be slower while caches warm up.
Reading the result: Speed Index, LCP and the performance score
Speed Index measures how quickly the visible part of the page fills in during load, and a lower number is better. Largest Contentful Paint (LCP) marks the moment the biggest image or text block in the viewport appears. The Lighthouse performance score out of 100 is a weighted blend of several lab metrics, including Speed Index, LCP and Total Blocking Time, so it can move even when Speed Index stays the same. Lighthouse calls 90 and above good, 50 to 89 needs improvement, and below 50 poor.
Why this free page speed test uses mobile
Google indexes the web with a smartphone crawler, and for many sites most visits now come from phones. Mobile tests are also stricter: PageSpeed Insights simulates a mid-range phone on a throttled connection, so a page that does well on mobile usually does well on desktop too. If you need a desktop result as well, run the URL at pagespeed.web.dev and switch to the Desktop tab.
The most common causes of a slow page
The same few problems come up again and again in PageSpeed Insights reports: images much larger than the space they're shown in, too much JavaScript running before the page becomes usable (often from themes, page builders, chat widgets and ad scripts), render-blocking CSS and web fonts, and slow server responses on uncached pages. On WordPress, a caching plugin and fewer plugins overall usually help most. On Shopify, apps you no longer use that still inject scripts are a frequent cause.
Will adding widgets slow my page down?
Any third-party script costs something. Keep the number of embeds low, load them after your main content where possible, and run this page speed test before and after adding one so you can see the real effect on your own page rather than relying on anyone's promise.
Why the number changes between tests
Each run loads the page fresh from Google's servers, so the result moves with your server's response time, third-party scripts that load differently each time, and ads or embeds that vary from one load to the next. Differences of a few hundred milliseconds are normal. A consistent jump after you change something is the signal worth acting on.
Show the result as a speed badge
Embed the result on your own site with one script line. Put it in your <head> and each page shows its own result, or place it in a footer or sidebar. It comes in 10 themes and four sizes, re-checks every 6 hours for registered sites and every 14 days otherwise, and works on WordPress, Shopify, Wix, Webflow, Ghost, Squarespace, Blogger and plain HTML.