JSON Formatter & Validator

Format, validate, and minify JSON with precise error messages.

Quick answer: Free online JSON formatter and validator. Beautify, parse, and minify JSON safely in your browser. Find syntax errors instantly with precise line numbers.

parsed locally — your JSON never leaves your browser

Paste JSON to pretty-print it with proper indentation, validate it with a precise error position, or minify it for transport — all in your browser, nothing uploaded.

How it works

  1. Paste your raw JSON string into the editor area.
  2. The tool will instantly validate the syntax and highlight any structural errors.
  3. Click "Format" to beautify the output, or "Minify" to strip whitespace for production.

Frequently asked questions

Why did my JSON fail validation due to a trailing comma?

The JSON specification is much stricter than JavaScript: it strictly forbids trailing commas, comments, and single quotes. The validator highlights exactly where this happens.

Is my sensitive data completely safe to paste?

Yes. The parsing executes locally in your browser memory. However, as a best practice, you should always avoid pasting live production secrets into any web tool.

What is the exact difference between JSON and JavaScript object literals?

JSON requires double-quoted keys and strings, and strictly limits data types (no undefined, no functions, no Dates).

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