Local Processing

JSON Formatter Online

Format, minify, validate, sort keys, escape, and unescape JSON locally.

Runs locallyNo uploadYour input is processed in your browser.

JSON Formatter

Format, minify, validate, sort keys, escape, and unescape JSON locally.

Examples

API Response Formatter

Input example

Compact response: {"status":"ok","data":{"id":42,"items":[{"sku":"A1","qty":2}]}}

Output example

Readable response: {
  "status": "ok",
  "data": {
    "id": 42,
    "items": [
      {
        "sku": "A1",
        "qty": 2
      }
    ]
  }
}

JSON Formatter processes this example in the browser and lets you inspect the result before copying it.

JSON Error Example

Input example

Broken JSON: {"name":"LumaTool", "enabled": true,}

Output example

Validation result: Error: trailing commas are not valid JSON.

JSON Formatter processes this example in the browser and lets you inspect the result before copying it.

Escape JSON for Code

Input example

JSON text: {"message":"Hello \n world"}

Output example

String literal: "{\"message\":\"Hello \\n world\"}"

JSON Formatter processes this example in the browser and lets you inspect the result before copying it.

Sort Keys Example

Input example

Unsorted config: {"timeout":30,"apiKey":"demo","baseUrl":"https://api.example.com"}

Output example

Sorted keys: {
  "apiKey": "demo",
  "baseUrl": "https://api.example.com",
  "timeout": 30
}

JSON Formatter processes this example in the browser and lets you inspect the result before copying it.

Minify before API request

Input example

Pretty payload: {
  "query": "tools",
  "limit": 10
}

Output example

Minified payload: {"query":"tools","limit":10}

JSON Formatter processes this example in the browser and lets you inspect the result before copying it.

Privacy note

This tool processes your input locally in your browser. Your text, code, file, or generated value is not uploaded to LumaTool servers.

How to use

Step 1. Paste JSON, an escaped JSON string, or a copied API response into the input box.
Step 2. Choose Format, Minify, Validate, Sort Keys, Escape for Code, or Unescape String.
Step 3. Check the result panel and validation message before using the output.
Step 4. Copy the result or download it as a JSON file.

Real-world examples

Format compact API responses copied from fetch, curl, Postman, or b...

Format compact API responses copied from fetch, curl, Postman, or browser DevTools.

Validate package

Validate package.json, tsconfig.json, app settings, and webhook payloads after manual edits.

Escape JSON snippets for unit tests, seed scripts, log fixtures, an...

Escape JSON snippets for unit tests, seed scripts, log fixtures, and code examples.

Common use cases

Format compact API responses copied from fetch, curl, Postman, or browser DevTools.
Validate package.json, tsconfig.json, app settings, and webhook payloads after manual edits.
Escape JSON snippets for unit tests, seed scripts, log fixtures, and code examples.
Sort keys before reviewing generated configuration or comparing payloads in pull requests.
Minify pretty JSON before sending it in an API request body or webhook tester.
Format, minify, validate, sort keys, escape, and unescape JSON locally.

FAQ

Is JSON Formatter free?

Yes. JSON Formatter is available as a free LumaTool web tool.

Do I need to sign in?

No sign-in is required for the public tool pages.

Will my input be uploaded?

No. This tool processes input locally in your browser.

Does it work on mobile?

Yes. The editor, buttons, and result areas are designed for mobile and desktop browsers.

Can I copy or download the result?

Ready tools include copy actions, and file-oriented tools include download actions where useful.

What is JSON Formatter best used for?

JSON Formatter is useful for focused developer tools tasks where you need a quick browser-based result without switching tools.

How is my input handled?

This tool processes your input locally in your browser. Your text, code, file, or generated value is not uploaded to LumaTool servers.

Can I use the output in production work?

Yes, but review the result before applying it to production systems. LumaTool helps with utility work, validation, and formatting, but final decisions stay with you.

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