Free Online Developer Tools
Fast, lightweight utilities for everyday development. Every tool runs entirely in your browser, so your data never leaves your device.
Data & JSON
JSON Formatter & Minifier
Beautify, validate, and minify JSON instantly with clear error messages.
Open Tool →JSON Escape / Unescape
Escape and unescape JSON strings for safe embedding in code and URLs.
Open Tool →JSON Diff
Compare two JSON documents side by side with highlighted differences, locally in your browser.
Open Tool →CSV to JSON Converter
Convert CSV to JSON and back, with configurable separators and header-row detection. 100% local.
Open Tool →YAML to JSON Converter
Convert YAML to JSON and back in your browser. No data is uploaded or stored.
Open Tool →Encoding
Base64 Encode / Decode
Convert text to and from Base64 with full Unicode support.
Open Tool →URL Encode / Decode
Percent-encode and decode URL components for query strings and paths.
Open Tool →String Escape / Unescape
Escape and unescape strings for JavaScript, HTML, and SQL targets in one click.
Open Tool →Expression & Parsers
Text
Crypto & IDs
MD5 / SHA-256 Hash Generator
Generate MD5 and SHA-256 hashes directly in your browser, no upload.
Open Tool →UUID / GUID / ULID / NanoID Generator
Generate random UUIDs, GUIDs, time-ordered ULIDs, and short URL-safe NanoIDs instantly in your browser. 100% local.
Open Tool →JWT Decoder
Decode JWT header and payload entirely in your browser. No signature validation, no upload, no storage.
Open Tool →