JSON Formatter & Beautifier

Prettify, minify, and validate JSON with syntax highlighting. Choose 2-space, 4-space, or tab indentation. Instant, browser-based.

JSON Formatter

Paste your JSON to prettify it with custom indentation, or minify it to a single line. Syntax highlighting included. Everything runs in your browser — your data never leaves your device.

Input

0 lines0 chars

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What is JSON Formatting?

JSON (JavaScript Object Notation) is the universal language of web APIs. Raw JSON from an HTTP response or a database is often compressed into a single line to reduce payload size, making it nearly impossible to read or debug by eye.

JSON formatting — also called prettifying or beautifying — adds indentation and newlines so each key-value pair occupies its own line. The result is a structured, human-readable document that is easy to inspect, review, and edit.

JSON minification is the reverse: it strips all unnecessary whitespace to produce the smallest possible representation. This is ideal before sending JSON to an API, embedding it in source code, or storing it in a database where every byte counts.

Minified (hard to read)

{"user":{"id":1,"name":"Alice","roles":["admin","editor"],"active":true,"score":null}}

Formatted with 2-space indentation (easy to read)

{
  "user": {
    "id": 1,
    "name": "Alice",
    "roles": [
      "admin",
      "editor"
    ],
    "active": true,
    "score": null
  }
}

How to Format JSON Online

  1. 1

    Paste or upload your JSON

    Copy your minified or unformatted JSON from an API response, config file, or log, and paste it into the editor above. You can also click "Upload" or drag & drop a .json file directly onto the editor.

  2. 2

    Choose your indentation style

    Select 2 spaces (most common), 4 spaces (Python/Java style), or Tab indentation using the buttons in the controls bar below the editor.

  3. 3

    Click "Format" or "Minify"

    Hit "Format" to prettify the JSON with your chosen indentation. Hit "Minify" to compress it to a single line — ideal for APIs, source code, or database storage.

  4. 4

    Copy or Download

    Use "Copy" to copy the result to your clipboard, or "Download" to save it as a .json file. Switch between the Formatted and Minified tabs to compare both versions at any time.

Frequently Asked Questions

Is my JSON data stored on your servers?▼

No. All processing happens entirely inside your web browser using JavaScript. Your data is never sent to our servers, logged, or stored anywhere.

What is the difference between JSON formatting and JSON minification?▼

Formatting (or prettifying) adds indentation and newlines to make JSON human-readable. Minification removes all unnecessary whitespace to produce the smallest possible representation — ideal for APIs and data storage.

Which indentation style should I use?▼

2 spaces is the most widely adopted convention (Prettier, Node.js, npm). 4 spaces is common in Python and Java ecosystems. Tabs are preferred by developers who want to configure their own display width in their editor.

Why is my JSON invalid?▼

Common causes include: single quotes instead of double quotes, trailing commas after the last item in an object or array, unquoted keys, or JavaScript-specific values like undefined, Infinity, or NaN. The error message will show the exact position of the first syntax error.

What is the maximum file size supported?▼

Because all processing runs in your browser, the practical limit is your browser's available memory. Files up to several megabytes format instantly. Very large files (>50 MB) may be slow depending on your device.

Does formatting change the data?▼

No. Formatting only changes the whitespace (indentation and newlines) around the data. The actual JSON values — strings, numbers, booleans, nulls, arrays, and objects — remain identical. You can verify this by switching between the Formatted and Minified tabs.

Is this tool free?▼

Yes, completely free with no registration or sign-up required. It is supported by non-intrusive advertising.

Frequently Asked Questions

Is my JSON data stored on your servers?

No. All processing happens entirely in your browser using JavaScript. Your data is never sent to our servers, logged, or stored anywhere.

What is the difference between JSON formatting and minification?

Formatting (prettifying) adds indentation and newlines to make JSON human-readable. Minification removes all unnecessary whitespace to produce the smallest possible JSON string — ideal for APIs and data storage.

Which indentation style should I use?

2 spaces is the most widely adopted convention (Prettier, Node.js, npm). 4 spaces is common in Python and Java. Tabs let each developer configure their preferred display width in their editor.

Why is my JSON invalid?

Common causes include: single quotes instead of double quotes, trailing commas after the last item, unquoted keys, or JavaScript-specific values like undefined, Infinity, or NaN.

Does formatting change the data?

No. Formatting only changes the whitespace. The actual JSON values — strings, numbers, booleans, nulls, arrays, and objects — remain identical.