JSON Formatter & Validator
Paste JSON to format it with proper indentation, minify it to one line, or validate it. Errors point to the exact position so you can fix them fast.
What this tool does
- Beautify with 2-space, 4-space, or tab indentation
- Minify to a single line for transport
- Validate with the exact error position and a clear message
- Parsed entirely in your browser — paste production data safely
Also known as: json beautifier, json validator, json pretty print.
Frequently asked questions
Is my JSON sent anywhere?
Yes. Everything runs in your browser with JavaScript — nothing you type or paste is uploaded, logged, or sent to a server. You can disconnect from the internet after the page loads and it still works.
Why does valid-looking JSON fail?
Strict JSON forbids trailing commas, single quotes, comments, and unquoted keys. The error message points to the position so you can spot the stray comma or quote that JavaScript's JSON.parse rejects.
Can it handle large files?
Yes, within your browser's memory — multi-megabyte JSON formats fine on a normal laptop. Since there is no upload, the only limit is the tab's available memory.
Do I need to sign up?
No. There is no account, no email, and no paywall. Open the page and use it.