What is Google PageSpeed Insights and how do you use it for SEO?
Google PageSpeed Insights is a free tool that tests your website speed and scores it against Google's Core Web Vitals. Enter a URL, pick mobile or desktop, and the tool returns a score out of 100 for each vital plus a list of specific fixes that would make your site faster.
If you have never run it before, start with your homepage and your most important sales or enquiry pages. The tool takes less than a minute to produce its report.
Where to find PageSpeed Insights
The tool lives at https://pagespeed.web.dev and does not need a login, an account or any setup. Paste in any public URL, choose whether to test the mobile or desktop version, and click Analyse. The mobile test matters more: Google uses the mobile version of your pages for indexing and ranking, so a poor mobile score affects your search visibility directly.
What the test measures
PageSpeed Insights scores your page against three Core Web Vitals metrics. LCP (Largest Contentful Paint) measures how long the main content takes to load. A good LCP is under 2.5 seconds. INP (Interaction to Next Paint) replaced FID in 2024 and measures how responsive your page feels when someone taps or clicks. A good INP is under 200 milliseconds. CLS (Cumulative Layout Shift) tracks how much the content jumps around as it loads. A good CLS stays below 0.1.
Each metric gets a score band: green (good, passing Core Web Vitals), amber (needs improvement) or red (poor, failing). The report then lists every element that is dragging the score down, ordered by potential impact.
What the fix list tells you
Below the scores, PageSpeed Insights shows the specific files and settings causing the problems. Typical fixes include compressing large images, removing unused CSS or JavaScript, enabling browser caching, using next-generation image formats and deferring off-screen images. Each suggestion includes a link to the Google developer documentation so your developer can implement the change.
The tool also checks a handful of best practices: whether your page uses HTTPS, whether it loads plugins that could slow things down, and whether images have explicit width and height set to prevent layout shifts.
Why speed matters for SEO
Google has used page speed as a ranking factor since 2010 and the Core Web Vitals update in 2021 made it a direct ranking signal. A slow site not only hurts your position in search results; it also increases bounce rate. Research consistently shows that a one-second delay in mobile load time can reduce conversions by up to 20%. For a small business running SEO packages from GBP 980 per month, every second of load time costs money in lost traffic and lost leads.
What PageSpeed Insights cannot tell you
The tool is limited to a single page at a time. It does not crawl your whole site, it does not check for broken links, missing meta data or duplicate content, and it does not show how your rankings or traffic are trending. For that you need a broader set of free tools: Google Search Console for search performance, Google Analytics 4 for traffic and user behaviour, and a site audit tool for technical faults. Our free SEO report at https://victory.digital/run-a-seo-report bundles those checks into one plain-language report.
How Victory Digital uses PageSpeed Insights
Speed optimisation is part of every technical SEO audit we run. We use PageSpeed Insights alongside Lighthouse reports and real user monitoring to identify the changes that will have the biggest impact on rankings and user experience. If your Core Web Vitals scores need work, we can plan the fixes as part of an SEO programme.
See our SEO packages and pricing at https://victory.digital/seo-packages, or run your own free SEO report at https://victory.digital/run-a-seo-report.
What are your Feelings?
Share your reaction
Click a reaction to share how useful this article was.