Website Image Speed Test - Beautiful & easy free analysis of the images on your page
Checkbot - Checkbot will boost the SEO, speed and security of your site by checking you're following 50+ web best practices. Browser extension with free and paid plans.
Pingo - Optimize images for the web quickly 🖼️⚡
Smaller - Make your websites load faster
Dither Me This - Reduce image file sizes in a stylish old-school way.
Global Website Speed Test - Test website load speed from 18 cities, including 3 in China