Developer Tools
A collection of free developer utilities that run entirely client-side. Beautify and validate JSON, encode and decode Base64, escape or unescape URLs, decode JWT tokens to inspect their payload, generate RFC-4122 UUIDs in bulk, and build or debug regular expressions with live highlighting. Built for speed, privacy and zero configuration — perfect for API work, debugging and everyday coding.
JSON Formatter
Format, validate and minify JSON with syntax error highlighting. Free online tool for developers.
Base64 Encode / Decode
Encode text to Base64 or decode Base64 back to text instantly in your browser. Supports UTF-8.
URL Encode / Decode
Encode text for safe use in URLs or decode URL-encoded strings back to readable text.
UUID Generator
Generate RFC-4122 version 4 UUIDs in bulk. Create one or thousands of unique identifiers instantly.
Regex Tester
Test regular expressions against any text with live match highlighting and capture groups.
JWT Decoder
Decode JSON Web Tokens (JWT) and inspect the header and payload. No verification, fully client-side.
HTML Entity Converter
Encode or decode HTML entities (&, <, >, " …).
Cron Parser
Explain a cron expression and preview its next run times.
Chmod Calculator
Convert between numeric and symbolic file permissions.
SQL Formatter
Pretty-print and format messy SQL queries.
JWT Generator
Create a signed HS256 JWT from header, payload and secret.