DevToolbox

JSON Formatter

Format, beautify, minify, and validate JSON instantly in your browser.

Processed locally in your browser

Input

Output

What is the JSON Formatter?

The JSON Formatter takes raw, minified, or messy JSON and turns it into a cleanly indented, readable document. JSON (JavaScript Object Notation) is the most common data interchange format on the web, but API responses and log payloads usually arrive as a single dense line that is painful to read and debug.

This tool parses your JSON with the browser's native parser, so validation is exact — if it formats, it is valid JSON. You can choose 2-space, 4-space, or tab indentation, minify formatted documents back to a single line, and download the result as a .json file.

Everything happens locally in your browser. Your data is never uploaded to a server, which makes it safe to format API responses, configuration files, and internal payloads.

How to use the JSON Formatter

  1. Paste your JSON into the input editor (or click Example to load a sample).
  2. Choose your preferred indentation: 2 spaces, 4 spaces, or tabs.
  3. Click Format to beautify, or Minify to compress to a single line.
  4. Copy the result to your clipboard or download it as a .json file.

Examples

Minified input

{"id":42,"name":"Ada","tags":["dev","math"]}

Formatted output (2 spaces)

{
  "id": 42,
  "name": "Ada",
  "tags": [
    "dev",
    "math"
  ]
}

Frequently asked questions

Is my JSON sent to a server?

No. Parsing and formatting run entirely in your browser using JavaScript's built-in JSON functions. Nothing you paste ever leaves your machine.

Why does my JSON fail to format?

The most common causes are trailing commas, single quotes instead of double quotes, unquoted keys, and comments — none of which are allowed in strict JSON. The error message shows the line and column where parsing failed.

Does formatting change my data?

No. Formatting only changes whitespace. Key order and values are preserved exactly as the parser reads them.

How large can my JSON be?

The tool comfortably handles documents of several megabytes. Extremely large files (tens of MB) may be slow because browsers parse them on the main thread.

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