Webpage Test is an open source project that is primarily being developed and supported by Google as part of make the web faster.
Run a free website speed test from multiple locations around the globe using real browsers (IE and Chrome) and at real consumer connection speeds.
PageSpeed Insights analyzes the content of a web page, then generates suggestions to make that page faster.
PageSpeed Insights measures the performance of a page for mobile devices and desktop devices. It fetches the url twice, once with a mobile user-agent, and once with a desktop-user agent.