JSON formatter
Paste JSON to see whether it parses, then format it with the indentation you choose or minify it onto one line.
It runs in your browser. What you enter stays on this device.
How to use it
- 1Paste or type JSON into the box.
- 2Choose Format, Minify, or Validate only.
- 3Pick 2 spaces, 4 spaces, or tabs when you want a formatted result.
- 4Choose Apply. Copy the result or download it as a JSON file.
When it helps
- Make a minified API payload readable before you edit it.
- Strip extra space before pasting JSON into a request.
- Find the line and column of a syntax error.
Good to know
- The input stays under 1 MB so the page can keep responding.
- Object key order is preserved. Keys are not sorted.
- JSON numbers are parsed as JavaScript numbers. Integers larger than 9007199254740991 (2^53 − 1) can lose precision, so a long identifier may not come back identical.
- Comments and trailing commas are not valid JSON, so they are reported as errors.
Questions
Is my JSON uploaded?
No. Parsing and formatting happen in this browser. Kiln does not send the text to a server or include it in analytics.
What does Validate only do?
It checks the syntax and, when the JSON is valid, shows a formatted copy. It does not change the text in the input box.
Can a large integer change?
Yes. Parsing uses JavaScript numbers, which cannot represent every integer above 9007199254740991 exactly. A long ID can come back different even when the JSON is valid.
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