Free Developer Tools That Run 100% in Your Browser — No Backend, No Tracking

I got tired of developer tool websites with ads, tracking, and server-side processing. So I built my own. DevTools.run 22 browser-based developer tools. Everything runs client-side — nothing is sent to a server. Try them → The Tools Text & Data JSON Formatter & Validator — paste, format, minify, syntax highlighting Base64 Encoder/Decoder — text and file support URL Encoder/Decoder — encodeURI vs encodeURIComponent YAML/JSON Converter — bidirectional with full parser Text Diff — side-by-side line diff with highlighting Crypto & Security Hash Generator — MD5, SHA-1, SHA-256 via Web Crypto API JWT Decoder — inspect header, payload, signature Password Generator — configurable with strength meter UUID Generator — bulk v4 UUIDs, toggle hyphens Developer Regex Tester — real-time match highlighting SQL Formatter — keyword uppercasing, indentation Cron Expression Parser — human-readable with next runs Unix Permissions Calculator — numeric + symbolic Markdown Preview — live rendering Utilities U