What is a JSON formatter?

A JSON formatter turns compact, single-line, or inconsistently indented JSON into a readable structure. It adds line breaks and indentation without changing property names, values, or array order. JSON formatter, JSON beautifier, and JSON pretty printer usually describe the same operation.

This formatter accepts strict JSON, including documents whose root value is a string, number, boolean, or null. Invalid JSON must be corrected before it can be formatted.

How to format JSON online

Paste JSON into the input editor, open a .json or .txt file, or load the example.
Open Settings to choose 2 spaces, 4 spaces, or Tab indentation.
Select Format JSON.
Copy the formatted result or download it as a .formatted.json file.

Errors are reported with their line and column. Select a diagnostic to move the input editor to the relevant source position.

JSON formatting example

Input:

{"project":"Bitty Coder","active":true,"tags":["json","browser"],"settings":{"indent":2,"optional":null}}

Formatted with 2 spaces:

{
  "project": "Bitty Coder",
  "active": true,
  "tags": [
    "json",
    "browser"
  ],
  "settings": {
    "indent": 2,
    "optional": null
  }
}

JSON formatter vs beautifier vs minifier

Formatter, beautifier, and pretty printer are different names for adding readable whitespace to JSON. A validator checks whether the syntax is valid, while a JSON Minifier removes insignificant whitespace to create compact JSON.

Formatting automatically performs strict syntax validation. Use the dedicated JSON Validator when you only need a validation report and do not need formatted output.

Common JSON formatting errors

Strict JSON requires double-quoted property names and string values. It does not allow trailing commas, comments, single-quoted strings, undefined, or JavaScript expressions. Objects and arrays must be closed correctly, and adjacent items must be separated by commas.

The formatter reports these problems instead of guessing how to change the data. If the input contains several syntax problems or non-standard JSON, use JSON Repair and review the repaired result before formatting it.

Does formatting change JSON data?

Formatting should change whitespace only. This tool scans the original JSON tokens instead of converting values with JSON.parse() and JSON.stringify(), so it preserves large integers, decimal spelling, exponent notation, string escapes, duplicate property tokens, property order, and array order.

Compatibility warnings identify values that other JavaScript software may interpret inconsistently, but the formatter does not silently rewrite them.

Private browser processing

Formatting, validation, file reading, copying, and downloading happen locally in your browser. Your JSON is not uploaded, stored, placed in the page URL, or written to browser storage. Refreshing or closing the page clears the input and output.

JSON formatter FAQ

What is the difference between a JSON formatter and a JSON beautifier?

There is usually no difference. Both names describe adding indentation and line breaks to make valid JSON easier to read.

Does formatting JSON change its data?

No. This formatter changes insignificant whitespace while preserving the original JSON tokens, keys, values, and array order.

Can a JSON formatter fix invalid JSON?

This formatter locates syntax errors but does not automatically change invalid input. Use JSON Repair when you intentionally want common problems repaired.

Should JSON use 2 or 4 spaces?

Both are valid. Two spaces produce a more compact document, while four spaces make nested levels more visually distinct. Use the style required by your project.

Is my JSON uploaded to a server?

No. The document remains in browser memory and is cleared when you refresh or leave the page.

JSON Formatter