PageSpeed Insights

pagespeed is addon for firebug (debugger addon for mozilla firefox ) for analyzing of page loading process and suggesting to webmaster how speed up page loading. javascript obfuscating, image resizing, css merging and vise versa.

Free Open Source Mac OS X Windows Linux Chrome Firefox Firebug

Gtmetrix

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...

Free Web

WebPagetest

Run a free website speed test from multiple locations around the globe using real browsers (Firefox, IE, Chrome, Android and iOS) and at real consumer connection speeds....

Free Open Source Web

Yahoo! YSlow

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.

Free Open Source Mac OS X Windows Linux Chrome Firefox Safari Opera Firebug

Google Lighthouse

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.

Free Open Source Mac OS X Windows Linux

PageSpeedAlarm.com

Be notified if your Google PageSpeed falls.

Free Web

StatusCake Tools

StatusCake Tools allows you to check the speed and load time of your website. Simply enter the website URL and check one of the locations from around the world you want...

Free Mac OS X Windows Web

Site Relic

Site Relic is a FREE toolbox where you can test your website for performance & security in seconds without user registration.

Freemium Web