JSON Formatter & Beautifier

Paste minified or messy JSON and get it back neatly indented, one key per line. The formatter parses the text strictly by the JSON standard (RFC 8259) and rebuilds it from what it read, so numbers, escape sequences and key order stay exactly as written — even integers too big for JavaScript. If the JSON is broken you get the line, the column and a plain-English reason instead of output.

How to use this tool

1. Paste your JSON into the box (it is formatted as you type).
2. Pick 2 spaces, 4 spaces or tabs for indentation.
3. Optionally tick Sort keys alphabetically to make two files easier to compare.
4. For tsconfig.json-style files, tick Allow comments and trailing commas.
5. Copy the result, or fix the error at the line and column shown.

Formula

value = object | array | string | number | true | false | null

That is the whole JSON grammar. In the output each object member or array item sits on its own line, one indent deeper than its parent, with ": " after every key. Empty objects and arrays stay as {} and []. Strings and numbers are copied character for character.

Example

The input {"id":7,"tags":["a","b"],"ok":true} with 2-space indentation becomes 8 lines: "id": 7 and "ok": true sit two spaces in, the array items "a" and "b" four spaces in, and the closing ] and } line up under the line that opened them. With Sort keys ticked the order becomes id, ok, tags.