If your website feels sluggish, or you’ve heard that a slow site can hurt both visitors and search rankings, Google PageSpeed Insights is the easiest place to start diagnosing the problem. It’s a free tool that scans any web page and hands you a score along with a list of specific things slowing it down.
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You don’t need to be a developer to use it or to understand most of what it tells you. This guide walks through how to run a test, what the score and metrics actually mean, and which fixes are worth prioritizing first.
Quick Answer
Go to pagespeed.web.dev, paste in your page’s URL, and click Analyze. You’ll get a performance score for both mobile and desktop, plus a prioritized list of ‘opportunities’ and ‘diagnostics’ explaining what to fix. Focus on the highest-impact items first, especially anything related to images, unused code, or server response time.
Running Your First Test
Open pagespeed.web.dev in any browser. Enter the exact URL of the page you want to check, whether that’s your homepage or a specific landing page, and click Analyze. The tool will test the page as if it were loading on a mobile device by default, then let you switch to the desktop results using a tab near the top of the report.
The scan takes a few seconds to run. Behind the scenes, Google is loading your page in a simulated environment and recording how it performs, then combining that with any real-world data it has collected from actual visitors using Chrome.
It’s worth testing your most important pages individually rather than just the homepage. An e-commerce product page or a blog post with lots of images often performs very differently than your homepage does.
Understanding Your Score and the Core Web Vitals
At the top of the report you’ll see a score from 0 to 100, color-coded green, orange, or red. This is a general shorthand, but the more useful information is below it: the Core Web Vitals, which are the three metrics Google considers most important for real-world user experience.
Largest Contentful Paint (LCP) measures how long it takes for the main content of the page to visibly load. A page loading in under 2.5 seconds is considered good. Interaction to Next Paint (INP) measures how quickly the page responds when someone clicks, taps, or types; under 200 milliseconds is good. Cumulative Layout Shift (CLS) measures how much content jumps around unexpectedly as the page loads, with a score under 0.1 considered good.
You’ll also notice two data sources in the report: ‘field data,’ which reflects how the page has actually performed for real visitors over the past month, and ‘lab data,’ which is a one-time simulated test. If you only just launched the page or don’t get much traffic, you may only see lab data — that’s normal, and it’s still useful for diagnosing issues.
Tips and Common Mistakes
Work through the ‘Opportunities’ and ‘Diagnostics’ sections in order of estimated savings. Image-related fixes, like compressing images or serving them in a modern format, are usually the fastest win and don’t require touching any code if your website platform (WordPress, Shopify, Squarespace, etc.) has an image optimization plugin or built-in setting.
Don’t chase a perfect 100 score. It’s a common trap to spend hours trying to squeeze out the last few points when your time is better spent on the two or three fixes with the biggest real-world impact on load time.
Test more than once. Scores can fluctuate slightly from run to run depending on network conditions during the test, so don’t panic over a small dip — look for consistent trends over time instead.
If a recommendation mentions render-blocking scripts, unused CSS, or server response time and it’s beyond your comfort level, that’s a good moment to loop in your web host’s support team or a developer. You’ve still done the valuable part: identifying exactly what’s slow and why.
Explore more: More Digital Strategy guides.
Google PageSpeed Insights FAQs
Is Google PageSpeed Insights free?
Yes, it’s completely free to use at pagespeed.web.dev, with no account or sign-up required.
Does my PageSpeed score directly affect my Google ranking?
Page experience and loading speed are one of many factors Google considers, but content relevance and quality generally matter more. Still, a faster site improves the experience for visitors and can reduce people leaving before the page finishes loading.
Why do I get a different score on mobile than on desktop?
Mobile devices are tested with slower simulated network and processing conditions than desktop, since that better reflects how many real visitors experience your site. It’s common and expected for the mobile score to be lower.
What’s a good PageSpeed score to aim for?
There’s no single required number, but landing in the green range, and passing the Core Web Vitals thresholds for LCP, INP, and CLS, is a reasonable practical goal for most small business sites.
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