JSON Formatter & Validator

Beautify, minify, and validate JSON — runs entirely in your browser.

This free JSON formatter and validator lets you beautify minified JSON, minify large JSON for production, and validate JSON syntax to catch errors before they reach your app. Everything runs in the browser — nothing leaves your machine.

Common uses:

Output

Frequently Asked Questions

How do I format JSON?
Paste your JSON into the input box and click Beautify. The tool will re-format it with 2-space indentation, making it human-readable.
What does the JSON validator check?
The validator checks for valid JSON syntax — missing commas, unclosed brackets, unquoted keys, trailing commas, and other parse errors. It reports the error message returned by the browser's JSON parser.
Can I minify JSON?
Yes. Click Minify to strip all unnecessary whitespace. This reduces JSON file size for API responses and storage.
Does this tool send my JSON anywhere?
No. All formatting and validation runs in your browser using the built-in JSON.parse and JSON.stringify functions. Nothing is transmitted to any server.
What is the difference between beautify and minify?
Beautify adds consistent indentation and line breaks so the JSON is easy to read. Minify removes all whitespace to produce the smallest possible JSON string — useful for production APIs and storage.
Why does my JSON show a parse error?
Common causes: trailing commas after the last item in an array or object, single quotes instead of double quotes, unquoted keys, or missing commas between items. The error message will indicate the position of the problem.

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