MachMetrics!

Pingdom web site monitoring and other infrastructure for you and instantly let you know when anything goes wrong. Measure uptime, downtime, and the performance of your website as experienced by visitors.

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.

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.

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. You can run simple tests or perform advanced testing including multi-step transactions, video capture, content blocking and much more. Your results will provide rich diagnostic information including resource loading waterfall charts, Page Speed optimization checks and suggestions for improvements.

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. YSlow grades web page based on one of three predefined ruleset or a user-defined ruleset. It offers suggestions for improving the pages performance, summarizes the pages components, displays statistics about the page, and provides tools for performance analysis, including Smush.it™ and JSLint.

Get free notifications if your page speed changes, fast and easy.

Free Cloud Load Testing Service, Speed Testing for Websites, Applications and APIs. Helps you run load and performance tests from within browsers in minutes.