royal.pingdom.com

Make the Web Faster

– Google Developers

Jank Free: Let's Make the Web Silky Smooth!

Advanced Performance Audits with DevTools - Paul Irish

Advanced Performance Audits With DevTools

Speedster

Run speed tests without sharing data with third party

Essential Image Optimization

An eBook by Addy Osmani

The Critical Request

– CSS-Tricks

The state of the web. A guide to improve performance

Calibre - Web performance monitoring