Free JSON Formatter & Validator — Online, No Sign-Up
Format, validate, and minify JSON instantly in your browser.
About this tool
Paste raw JSON to instantly format it with proper indentation, validate its syntax, and spot errors with clear inline messages. Switch to minify mode to compress JSON for production use. All processing is 100% client-side — your data never leaves your browser.
Key Features
- Instant JSON formatting with configurable indentation (2 or 4 spaces)
- Real-time syntax validation with descriptive error messages
- One-click minify mode to compress JSON for production
- Copy formatted output to clipboard instantly
- 100% browser-based — no data sent to any server
Frequently Asked Questions
Does this JSON formatter send my data to a server?
No. All JSON formatting and validation happens entirely in your browser using JavaScript. Your data is never sent to any server.
Can I validate JSON with this tool?
Yes. The tool validates your JSON in real time and shows descriptive error messages pointing to exactly where the syntax error is.
What is JSON minification?
Minification removes all unnecessary whitespace and newlines from JSON, reducing file size. This is useful when sending JSON over a network or embedding it in production code.
How large a JSON file can I paste?
The tool works entirely in your browser and can handle JSON of any size your browser's memory allows. There is no server-side limit.