Google Page Speed Tool

As part of Google’s drive to speed up the web, the Google Page Speed Tool is a free resource you can use to check page load times and performance. It is possible to carry out a comprehensive analysis of your site performance online, and a free Chrome extension is available for those who manage a number of different sites. The insights produced by the Page Speed Tool can help steer your site back towards web best practice, which is helpful for both your performance in Google and the experience of your website visitors.

https://developers.google.com/speed/pagespeed/