Lightning-Fast Web Performance
A free online lecture course by Scott Jehl. Learn to analyze site performance, fix issues, monitor for regressions, and deliver fast, responsive designs from the start.
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Responsive Image Breakpoints Generator
Easily generate the optimal responsive image dimensions. One image for all screen resolutions and different devices is not enough. An image per pixel is too much - so how can someone automatically choose the optimal responsive image sizes?
Lightning-Fast Web Performance
A free online lecture course by Scott Jehl. Learn to analyze site performance, fix issues, monitor for regressions, and deliver fast, responsive designs from the start.
BlurHash
BlurHash takes an image and gives you a short string that represents the placeholder for an image for a more seamless loading experience.
Polypane
Develop, debug and test websites and apps twice as fast. Know for sure your sites and apps work everywhere and for everyone.
Jpeg.io
Convert any major image format into a highly optimized JPEG.
ImageOptim
ImageOptim makes images load faster. Removes bloated metadata. Saves disk space & bandwidth by compressing images without losing quality.
Squoosh
Squoosh is an image compression web app that allows you to dive into the advanced options provided by various image compressors.
WebPageTest
Run a free website speed test from multiple locations around the globe using real browsers (IE and Chrome) and at real consumer connection speeds. You can run simple tests or perform advanced testing including multi-step transactions, video capture, content blocking and much more. Your results will provide rich diagnostic information including resource loading waterfall charts, Page Speed optimization checks and suggestions for improvements.
web.dev
Get the web's modern capabilities on your own sites and apps with useful guidance and analysis from web.dev.
Nibbler
Nibbler is a free tool for testing websites. Enter the address of any website and Nibbler will give you a report scoring the website out of 10 for key areas, including accessibility, SEO, social media and technology.
Google Mobile Speed Test
Test your mobile site speed in realistic conditions and receive actionable recommendations using this handy Google utility.