Test your website speed GTmetrix tells you how your website performs, why it's slow, and how to optimize it.

Think of Speed Index as a unified metric that accounts for many of the other metrics and audits. SI, on its own, does not give you much actionable information. However, it represents a …

Core Web Vitals are one of the key signals in Google's search ranking algorithm. A very poor performing website may not fare well in search results and can impact your revenue if fewer …

Uncover performance insights so you can make your site as fast as it can be with GTmetrix. Here’s a quick list of resources to get you on your way to optimization.

GTmetrix has numerous test servers located worldwide, which you are able to use for testing your site's performance. You can specify which test server to use by selecting a test server in the …

While this article focuses on three major Lighthouse tools, the overall rationale extends to any tool that uses Lighthouse to produce performance data. Here are some of the key differences …

GTmetrix offers detailed explanation of best practice speed optimizations as well as our own recommendations.

The GTmetrix Grade blends how fast your page performs (in terms of loading, interactivity, and visual stability) with how well it’s built for optimal performance.

Nov 21, 2025 · GTmetrix is powered by Google’s Lighthouse, the modern industry standard in website testing. Google’s own PageSpeed Insights (PSI) is a popular tool used for spot checks …

GTmetrix uses a real browser to load your page in its entirety, and then audits the data using Google Lighthouse. A report is generated containing performance data, insights, and …