Free, private developer tools.
DevToolbox is a growing collection of free developer utilities — formatters, encoders, generators and converters — that all run entirely in your browser.
Most online dev tools bury a simple utility under ads, sign-up walls, or worse, send your data to a server. DevToolbox does the opposite: every tool is 100% client-side JavaScript. Your JSON, JWTs, passwords and text are processed locally and never leave your device.
18+ everyday tools including a JSON formatter, Base64 converter, JWT decoder, regex tester, UUID generator and more — all free, fast and private. See all tools →
Have a tool idea or found a bug? Reach us via the contact page.