JSON Formatter
Beautify, validate and minify JSON instantly.
Free online JSON formatter and validator. Paste JSON to beautify it with proper indentation, catch syntax errors, or minify it. Runs entirely in your browser — nothing is uploaded.
How to use the JSON Formatter
- 01Paste or type your JSON into the input box.
- 02Choose Format to pretty-print it, or Minify to strip whitespace.
- 03If the JSON is invalid, the exact error and position are shown.
- 04Copy the result — your data never leaves your browser.
Frequently asked questions
Is my JSON uploaded to a server?
No. The formatter runs entirely in your browser using JavaScript. Your data never leaves your device, which makes it safe for sensitive payloads.
Why does it say my JSON is invalid?
The tool uses the same parser your browser uses. Common causes are trailing commas, single quotes instead of double quotes, or unquoted keys. The error message points to the position of the problem.
Is there a size limit?
There is no fixed limit. Because everything runs locally, very large files are only bounded by your device's memory.