Free Online Developer Tools
A growing collection of browser-only developer utilities. No signup, no backend, no data sent to servers — everything runs locally.
Developer Utilities
Format JSON, validate syntax, encode Base64, decode JWTs, encode URLs, and generate UUID v4 values without sending data to a server.
JSON Formatter
Free online JSON formatter, validator, and beautifier. Format, minify, validate, and copy JSON with syntax highlighting. No signup required.
JSON Validator
Free online JSON validator. Validate JSON syntax, find parsing errors, and verify JSON structure instantly.
Base64 Encoder Decoder
Encode and decode Base64 strings instantly with this free online Base64 converter.
JWT Decoder
Decode JWT tokens online. View headers, payloads, expiration times, and claims instantly.
URL Encoder Decoder
Encode and decode URLs instantly with this free online URL encoding tool.
UUID Generator
Generate secure UUID v4 identifiers instantly. Copy or download UUIDs for development use.