JSON Formatter

What it does

JSON Formatter checks that your text is valid JSON, then re-indents it or compresses it to one line. It changes only whitespace: numbers, key order and string escapes come out exactly as you typed them, so large IDs and values such as 1.10 are not rounded or rewritten.

How to use

1. Paste valid JSON into the input area.
2. Choose an indent size, then select Format or Minify. Ctrl+Enter also formats.
3. Copy the output when you are done.

Duplicate keys

A JSON object should not repeat a key, and most parsers silently keep only the last value. The formatter keeps every occurrence and warns you, so you can fix the source.

Privacy

The formatter uses your browser's built-in JSON parser and runs entirely on your device. No request is sent to a server with the text you enter.