JSON Formatter
Format, validate and beautify JSON online for free, with clear error messages for invalid JSON.
Paste JSON above, or upload a .json file.
Paste JSON to make it readable, shrink it, or check it for mistakes. Formatting indents every level so the structure is easy to follow. Minifying removes all spaces and line breaks for the smallest size.
How to format JSON
- Paste your JSON into the box, or open a .json file.
- Click Format to indent it, or Minify to compress it onto one line.
- Copy the result or download it as a file.
Finding errors
If the JSON is not valid, the tool says what is wrong and gives the line and column, so you can go straight to the problem. The usual causes are a comma after the last item, single quotes instead of double quotes, and names without quotes.
Frequently asked questions
Is my data sent anywhere?
No. The JSON is processed in your browser and never leaves your device, so it is safe for private data such as API responses and configuration files.
Does formatting change my data?
No. Only spaces and line breaks change. Names, values and their order stay the same.
Why is my JSON invalid?
Most often a trailing comma, single quotes, a missing quote or bracket, or a comment. JSON does not allow comments.
How large a file can it handle?
Files of several megabytes are fine on a computer. Very large files depend on the memory of your device.
Is it free?
Yes. There is no sign-up, no watermark and no daily limit.