{"id":4688,"date":"2026-07-01T21:10:41","date_gmt":"2026-07-01T18:10:41","guid":{"rendered":"https:\/\/fastpixel.io\/?p=4688"},"modified":"2026-07-01T21:10:43","modified_gmt":"2026-07-01T18:10:43","slug":"pagespeed-insights-vs-gtmetrix-vs-lighthouse-why-the-same-site-gets-three-different-scores","status":"publish","type":"post","link":"https:\/\/fastpixel.io\/fr\/blog\/pagespeed-insights-vs-gtmetrix-vs-lighthouse-why-the-same-site-gets-three-different-scores\/","title":{"rendered":"PageSpeed Insights vs. GTmetrix vs. Lighthouse: Why the Same Site Gets Three Different Scores"},"content":{"rendered":"

You test your site on Google PageSpeed Insights and it hands you a 99. Nice. So you paste the same URL into GTmetrix, and it comes back with a Grade A.<\/p>\n\n\n\n

Then, just to be thorough, you fire up Lighthouse in Chrome. Same page. This time it says 94.<\/p>\n\n\n\n

Three tools, one website, one testing session, and not a single number that matches.<\/p>\n\n\n\n

The natural reaction is to ask which tool is telling the truth. That’s the wrong question, though, and here’s why.<\/p>\n\n\n\n

Not one of them is broken. They just measure speed from different places, over different connections, with different assumptions baked in about what a “typical” visitor looks like. Figure out what each one is actually doing under the hood, and those mismatched scores stop being frustrating. They start telling you something.<\/p>\n\n\n\n

So let’s pull them apart. How each tool works, why the numbers drift, and how you read all three together instead of trusting one and ignoring the rest. Every example below comes from real reports run on fastpixel.io<\/a>.<\/p>\n\n\n\n

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