Free Online Developer Tools for JSON, Base64 & JWT
DataFormatter is a collection of free, privacy-first online developer tools for formatting, validating, converting, encoding and debugging data. Format JSON, decode JWTs, convert Base64 and URL, hash text, diff JSON or text, compile code and test APIs — all in one fast workspace that runs entirely in your browser. Nothing you paste is ever uploaded to a server, and there are no accounts, no signup and no usage limits.
Popular developer tools
API & debugging tools
Why DataFormatter?
- Runs in your browser — every tool is pure client-side JavaScript; there is no upload step for processing to happen.
- Free and unlimited — no accounts, no signup and no usage caps on any page.
- Fast — results compute in milliseconds because there is no round trip to a server.
- Private by design — data stays in your tab; share links are local URL fragments, never server storage.
Explore the toolbox
- Encoding & Decoding ToolsBase32, Base58, Base64, URL, HTML and UTF-8 in one workspace.
- Base64 ToolsImages, JSON, hex and binary to Base64 and back again.
- JSON ConvertersJSON into YAML, CSV, TSV, XML, Excel, Java, HTML and more.
- ParsersURL components, JSON trees, XML element trees and YAML.
- Random GeneratorsUUIDs, IPs, numbers, dates and realistic test data.
- String FunctionsCase, reverse, count, sort and 20+ more text utilities.
- Cryptography ToolsMD5 through SHA-512 and the SHA-3 family.
- Online CompilerWrite and run Dart, JavaScript and TypeScript in-browser.
- API ClientBuild and send REST requests straight from your browser.