JF

JSON Formatter / Validator

Developer Tools · Free · Runs entirely in your browser

Paste JSON — format (beautify), minify or validate it. Syntax errors show the exact spot. It all happens in your browser.

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Input
Result
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How to use — JSON Formatter / Validator

  1. Paste your JSON in the input box.
  2. Click Format — it beautifies with 2-space indentation.
  3. Use Minify to strip all spaces for compact JSON.
  4. If the JSON is invalid, a message with the exact error position appears.

FAQ

Why does it say my JSON is invalid?

Common mistakes: keys not in double quotes, a trailing comma after the last item, single quotes, or comments — none of these are allowed in JSON. The error message shows the exact position.

Is my JSON data uploaded anywhere?

No — parsing and formatting happen in the browser via JSON.parse/JSON.stringify. JSON containing API keys or sensitive data is safe too.

How large a JSON can this handle?

Several MB with ease — it's processed entirely in the browser. Very large files (50MB+) may be slow.

Is JSON5 or JSONC (with comments) supported?

No — this is a strict JSON validator (RFC 8259). Comments and trailing commas are invalid in standard JSON, so you'll get an error.

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