Free & open
Developer Tools
A small set of focused, no-nonsense utilities for everyday development tasks. Each one runs entirely in your browser — nothing you paste is uploaded.
JWT Decoder
Decode a token’s header, payload and claims, and verify an HMAC signature — without sending it anywhere.
Try JWT Decoder (opens in new tab)Base64 Converter
Encode and decode text using Base64 encoding. Perfect for handling binary data in text format.
Try Base64 Converter (opens in new tab)Diff Checker
Compare two texts and find differences. Ideal for code reviews and text comparison.
Try Diff Checker (opens in new tab)JSON Viewer
Format and validate JSON data. Makes complex JSON structures easy to read and understand.
Try JSON Viewer (opens in new tab)Support the project
Every tool here is free, carries no ads, and runs entirely in your browser — nothing you paste is uploaded anywhere. If they save you time, a coffee helps keep them online.
Buy me a coffee (opens in new tab)