Beautify, minify and validate JSON with the free JSON Formatter from Blanza Tools. Paste messy or compressed JSON to get clean, readable output — or find the exact line and column of a syntax error. Everything runs locally in your browser, so your data stays private.
Paste messy JSON and get clean, readable output — or find exactly where your syntax error is. Everything runs locally in your browser.
How to use
Paste your JSON into the input box.
Click Format to beautify it, Minify to compress it, or Validate to check it.
Copy the result or fix errors using the pinpointed error messages.
Frequently Asked Questions
Is my JSON uploaded to a server?
No. Formatting and validation happen entirely in your browser, so sensitive data never leaves your device.
What does the validator check?
It parses your JSON strictly and reports the exact error message with the line and column where the problem is — plus common causes like trailing commas.
What is the difference between format and minify?
Format adds indentation and line breaks so humans can read the JSON; minify removes all unnecessary whitespace so machines can transfer it as compactly as possible.
What causes “Unexpected token” errors?
The most common causes are trailing commas, single quotes instead of double quotes, unquoted object keys, and missing or extra brackets.
Is the JSON formatter free?
Yes — completely free, unlimited and no sign-up required.