JSON formatter & validator

Beautify, minify and validate JSON instantly — with clear error messages, 100% in your browser.

Format and validate JSON in one place

Whether you are debugging an API response, cleaning up a config file or just trying to read a wall of minified text, this JSON formatter makes it instant. Paste your JSON and choose Beautify to indent it neatly, Minify to collapse it to a single compact line, or Validate to confirm it parses — with a precise error message when it does not.

Everything runs locally with your browser's native JSON engine, so even sensitive payloads, tokens and customer data stay on your own device. No upload, no sign-up, no limits.

How to use the JSON formatter

Paste your JSON into the input box, then click Beautify to indent it, Minify to compress it, or Validate to check it. If the parser hits a problem, the error points you at the exact spot — a trailing comma, a single quote or a missing bracket — so fixing malformed JSON takes seconds instead of squinting at a wall of text. Copy the cleaned-up result and paste it straight back into your code or config.

Common real-world uses

Developers reach for a JSON beautifier to read API responses, tidy package.json and other config files, prepare request bodies for testing, and shrink payloads before shipping them. If you are also handling encoded data, the Base64 encoder/decoder and URL encoder pair naturally with this formatter, and you can browse the full set on the developer tools page.

Frequently asked questions

How do I format (beautify) JSON?
Paste your JSON and click Beautify. The tool re-indents it with 2 or 4 spaces so it is easy to read. If the JSON is invalid, you get a clear error message pointing to the problem.
What does minify do?
Minify removes all whitespace and line breaks to give you the smallest valid JSON on a single line — useful for config values, API payloads and saving bytes.
Is my JSON sent to a server?
No. The formatter runs entirely in your browser using the native JSON parser, so your data never leaves your device. That makes it safe for sensitive payloads.
Why does it say my JSON is invalid?
Common causes are trailing commas, single quotes instead of double quotes, missing brackets or unquoted keys. The error message tells you where parsing failed so you can fix it.
Can it pretty-print large API responses?
Yes. Paste a multi-megabyte API response and Beautify re-indents the whole structure so you can scan nested objects and arrays. Because parsing is native, even large payloads format in a fraction of a second.
Does it sort or change my keys?
No. Beautify and Minify preserve your key order and values exactly — they only change whitespace and indentation. The output is the same JSON, just reformatted for readability or size.
Can I choose the indentation size?
Yes. You can switch between 2-space and 4-space indentation when beautifying, matching whatever style your codebase or linter expects before you paste the result back.
Does it work offline?
Once the page has loaded, the formatter keeps working without a connection because all parsing happens locally in the browser. There is no API call behind the Beautify, Minify or Validate buttons.

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By Narender Chaudhary, Editorial & Product Lead · Updated June 2026

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