About JSON Formatter Online
Built for developers who want a fast, trustworthy JSON tool with no friction.
What is this?
JSON Formatter Online is a free browser-based tool for formatting, validating, minifying, and converting JSON data. It supports indentation styles (2 spaces, 4 spaces, tab, compact), key sorting, JSON repair, escape/unescape, and conversion to XML, CSV, YAML, and TypeScript interfaces.
How it works
Everything runs locally in your browser using JavaScript. When you paste or upload JSON, it never leaves your device - there is no backend, no upload endpoint, and no network request involved in processing your data. The tool works offline once the page has loaded.
Why we built it
Most online JSON tools either send your data to a server, show intrusive ads, require an account, or load slowly. We wanted a tool that respects developer workflow: instant, private, and reliable. JSON Formatter Online has no ads, no signup, no paywalls, and no cookies beyond what the browser requires.
Standards compliance
JSON validation follows RFC 8259, the current IETF standard for JSON. CSV output follows RFC 4180. TypeScript interface generation targets TypeScript 5.x syntax.
Contact & support
Found a bug or have a feature request? Get in touch.