KeyCDN HTTP Header Checker

Local file sharing in the browser that discovers nearby devices and sends files directly.

HTML5 internet speed test that measures download, upload, ping and jitter.

Sends files and text between devices on the same network or via a room code, with no signup.

Peer-to-peer file transfer that gives you a link; the data goes straight from sender to receiver.

Demo of the UAParser.js library that detects browser, engine, OS, device and CPU from a user-agent string.

Cheat sheet of easing functions with previews and ready-to-use CSS values.