SEO Speed Tool and Performance Tools
WebPageTest
Allows you to compare performance of one or more pages in controlled lab environment, and deep dive into performance stats and test performance on a real device. You can also run Lighthouse on WebPageTest.
TestMySite
Allows you to diagnose webpage performance across devices and provides a list of fixes for improving the experience from Webpagetest and PageSpeed Insights.
Speed Scorecard
Allows you to compare your mobile site speed against your peers in over 10 countries. Mobile site speed is based on real-world data from the Chrome User Experience Report.
Impact Calculator
Allows you to estimate the potential revenue opportunity of improving your mobile site speed, based on benchmark data from Google Analytics.
Chrome Developer Tools
Allows you to profile the runtime of a page, as well as identify and debug performance bottlenecks.