JSON Formatter & Validator

Format, validate, minify, and compare JSON instantly. Tree view, syntax highlighting, real-time error detection.

Client-side Privacy-first No limits
Input
Output

Paste JSON and tap Format JSON above

Ready Lines: 0 Size: 0 B Indent:
Runs entirely in your browser. No data sent to any server.

Paste or upload JSON to format, minify, validate, or explore as a tree. Everything runs client-side — your data never leaves your browser.

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Frequently Asked Questions

Is this JSON formatter free to use?

Yes, our JSON formatter is completely free to use with no registration required.

Does this tool validate JSON syntax?

Yes, the tool validates JSON syntax in real-time and displays detailed error messages with line numbers if your JSON is invalid.

Can I use this JSON formatter offline?

Yes, after loading the page once, the tool works entirely in your browser with no data sent to any server.

What is the maximum JSON size supported?

The tool can handle JSON files up to several megabytes, limited only by your browser's memory.

What is the difference between format and minify?

Format (prettify) adds indentation and line breaks to make JSON human-readable. Minify removes all unnecessary whitespace to make the file as small as possible.

Does this tool support JSON5?

Currently, we support standard JSON format. JSON5 features like comments and trailing commas are not supported.