"PhantomJS-based web performance metrics collector and monitoring tool"

List of various Web Performance Tools

"Charles is an HTTP proxy / HTTP monitor / Reverse Proxy that enables a developer to view all of the HTTP and SSL / HTTPS traffic between their machine and the Internet. This includes requests, responses and the HTTP headers (which contain the cookies and caching information)."

"Sitespeed.io is an open source tool that helps you analyze your website speed and performance based on performance best practices and metrics. It collects data from multiple pages on your website, analyze the pages using the rules and output the result as HTML or JUnit XML."