Free Developer Tools
The everyday dev toolbox: format, encode, decode, test and generate — without leaving the browser. Every tool processes your input locally, so tokens, payloads and queries never touch a server.
JSON Formatter
Format, beautify and minify JSON with instant validation — all in your browser.
DeveloperBase64 Encoder / Decoder
Encode text to Base64 or decode it back — instantly and privately in your browser.
DeveloperURL Encoder / Decoder
Encode or decode URLs and query components instantly and privately in your browser.
DeveloperHash Generator
Generate SHA-1, SHA-256, SHA-384 and SHA-512 hashes of any text — privately in your browser.
DeveloperJWT Decoder
Decode and inspect JWT header, payload and expiry — entirely in your browser.
DeveloperCron Expression Builder
Build and understand cron schedules in plain English, with the next run times.
DeveloperUUID Generator
Generate UUID v4, v7 and ULID identifiers in bulk — instantly and locally.
DeveloperText Diff Checker
Compare two texts and see exactly what changed — line by line or word by word.
DeveloperJSON to TypeScript
Generate TypeScript interfaces from any JSON — instantly and locally.
DeveloperRegex Tester
Test regular expressions live, highlight every match, and understand what they do.
DeveloperSQL Formatter
Beautify and format messy SQL queries — across dialects, in your browser.
DeveloperMarkdown Editor
Write Markdown with a live preview and export clean HTML.
DeveloperWhat you'll find here
The tools you reach for a dozen times a day, minus the sketchy ad-maze sites. The JSON Formatter pretty-prints and validates payloads with precise error locations. The Regex Tester shows matches and capture groups live as you type the pattern. The Base64 Encoder / Decoder and URL Encoder / Decoder handle the encoding round-trips, and the JWT Decoder splits a token into readable header and payload instantly.
Why these developer tools are different
You should never paste a bearer token or a production payload into a website that sends it to a server. These tools don't — every operation runs client-side in your browser, so your data stays on your machine. No account, no rate limits, no "upgrade to format files over 1 MB".
They're also fast in the way dev tools should be: output updates live, and every result has a copy button.
Popular picks
- The UUID Generator produces one or a batch of v4 UUIDs, copy-ready.
- The SQL Formatter untangles machine-generated queries into readable SQL.
- The Cron Expression Builder translates between cron syntax and plain English — in both directions.
- Comparing two configs? The Text Diff Checker highlights exactly what changed.
Bookmark the ones you use — they'll still be free tomorrow.