The best open source alternative to GTmetrix is Google Lighthouse. If that doesn't suit you, our users have ranked more than 50 alternatives to GTmetrix and seven of them is open source so hopefully you can find a suitable replacement. Other interesting open source alternatives to GTmetrix are WebPageTest, PageSpeed Insights, Yellow Lab Tools and Yahoo! YSlow.
Lighthouse is an open-source, automated tool for improving the quality of web pages. You can run it against any web page, public or requiring authentication. It has audits for performance, accessibility, progressive web apps, SEO and more.
Run a free website speed test from around the globe using real browsers at consumer connection speeds with detailed optimization recommendations.
PageSpeed Insights (PSI) reports on the performance of a page on both mobile and desktop devices, and provides suggestions on how that page may be improved.
free, simple, fast, report simple to read
YSlow analyzes web pages and suggests ways to improve their performance based on a set of rules for high performance web pages. YSlow is a Firefox add-on integrated with the Firebug web development tool.
Falco helps you monitor, analyze, and optimize your websites. Falco runs performance audits several times a day, and offers a historical overview to monitor its evolution and enables you to access the full WebPageTest results of each audit, allowing you to analyze the...
Sitespeed.io is an open source tool that helps you analyse and optimise your website speed and performance, based on performance best practices.
United States
France
EU
works nicely, lot of indicators & suggestions, for free