Get an insight into the inner-workings of a given website: uncover potential attack vectors, analyse server architecture, view security configurations, and learn what technologies a site is using.


PageGym is described as 'A free page speed test and load behavior analyzer, that also allows you to perform optimization experiments without making changes to your code' and is an website in the development category. There are more than 10 alternatives to PageGym, not only websites but also apps for a variety of platforms, including SaaS, Self-Hosted, Google Chrome and Mozilla Firefox apps. The best PageGym alternative is Web Check, which is both free and Open Source. Other great sites and apps similar to PageGym are Google Lighthouse, PageSpeed Insights, GTmetrix and WebPageTest.
Get an insight into the inner-workings of a given website: uncover potential attack vectors, analyse server architecture, view security configurations, and learn what technologies a site is using.


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.




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.

GTmetrix is a free tool that analyzes your page's speed performance. Using Page Speed and YSlow, GTmetrix generates scores for your pages and offers actionable recommendations on how to fix them.


Run a free website speed test from around the globe using real browsers at consumer connection speeds with detailed optimization recommendations.



DebugBear monitors website performance and provides technical insight on how to improve it. The product helps customers deliver a great user experience and rank higher in Google.




SpeedVitals is a website performance evaluation tool for improving Core Web Vitals. SpeedVitals uses Lighthouse to measure the Lab Data and Chrome's User Experience API to measure Field Data. It has features like Multi-Device & Multi-Location Testing, Waterfall Charts...




Sitespeed.io is an open source tool that helps you analyse and optimise your website speed and performance, based on performance best practices.
Monitor the front-end performance and build of your website. Compare yourself to others and beat the competition.


