SPOF-O-Matic : Chrome extension for detecting and simulating frontend Single Points Of Failure. Detects likely third-party single points of failure as you browse and...
WebPagetest : Run a free website speed test from multiple locations around the globe using real browsers (IE and Chrome) and at real consumer connection speeds.
Arora : Arora is a lightweight cross-platform web browser. It's free (as in free speech and free beer). Arora runs on Linux, embedded Linux, FreeBSD, Mac OS X...
webhint : webhint is a linting tool that will help you with your site's accessibility, speed, security and more, by checking your code for best practices and co...
Minimize round-trip times : An article on the best practices to apply in order to minimize HTTP round-trip times
The easiest way to measure your performance budget.