Smaller - Make your websites load faster
Web Load Speed Test - Test your website load speed from 6 locations at once
Cloudinary - Cloudinary is a cloud-based service for hosting videos and images designed specifically with the needs of web and mobile developers in mind.
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.
speedtest-cli - Test your download speed using SpeedTest on the command-line
Holly Website Audit - Free, brandable website audit for your potential clients