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JSON Formatter

Format, validate, and minify your JSON data with syntax highlighting and error detection.

Input JSON

Upload JSON Fileor drag and drop

Output

What is JSON and Why Format It?

JSON (JavaScript Object Notation) is the most widely used data interchange format on the web. It's used by REST APIs, configuration files, NoSQL databases, and modern web applications. However, JSON data is often minified or poorly formatted, making it difficult to read and debug.

A JSON formatter (also called a JSON beautifier or JSON prettifier) transforms compact, hard-to-read JSON into a clean, indented structure. This makes it easier to understand the data hierarchy, spot errors, and work with complex nested objects and arrays.

How to Use the JSON Formatter

  1. Paste your JSON code into the input box or upload a .json file.
  2. Click Format to beautify the JSON with proper indentation.
  3. Click Minify to remove whitespace and reduce file size.
  4. Click Validate to check for syntax errors.
  5. Copy the formatted output or download it as a file.

Example: Before and After Formatting

Before (minified):

{"name":"John Doe","age":30,"email":"john@example.com","address":{"street":"123 Main St","city":"New York"}}

After (formatted):

{
  "name": "John Doe",
  "age": 30,
  "email": "john@example.com",
  "address": {
    "street": "123 Main St",
    "city": "New York"
  }
}

Key Features

  • Beautify: Formats JSON with 2-space indentation for readability.
  • Minify: Compresses JSON by removing unnecessary whitespace.
  • Validate: Checks if your JSON is syntactically correct and highlights errors.
  • Syntax Highlighting: Color-coded output for easier reading.
  • Privacy-Focused: All processing happens in your browser. No data is sent to any server.
  • Fast: Instant formatting with no server delays.

Common JSON Errors and How to Fix Them

Our validator detects common JSON syntax errors:

  • Trailing commas: JSON doesn't allow commas after the last item in an object or array.
  • Single quotes: JSON requires double quotes for strings and property names.
  • Unquoted keys: All object keys must be wrapped in double quotes.
  • Missing commas: Items in arrays and objects must be separated by commas.
  • Unclosed brackets: Every opening bracket must have a matching closing bracket.

Related Tools

Explore other JSON and data conversion tools:

Learn More

Check out our guides for more tips and tutorials:

Frequently Asked Questions

What is a JSON Formatter?

A JSON Formatter is a tool that takes raw, minified, or poorly formatted JSON data and makes it readable by adding proper indentation and newlines. It helps developers quickly understand the structure of JSON data, debug API responses, and work with configuration files more efficiently.

Is my data safe?

Yes, this tool processes all data locally in your browser. No JSON data is sent to any server. Your data never leaves your device, ensuring complete privacy and security. This is especially important when working with sensitive data like API keys, user information, or proprietary business data.

How do I validate JSON?

Simply paste your JSON into the input box. The tool will automatically check for syntax errors and highlight them if present. Common errors include missing commas, unclosed brackets, trailing commas, unquoted keys, and single quotes instead of double quotes. The validator will show you exactly where the error occurs.

What's the difference between formatting and minifying JSON?

Formatting (beautifying) adds indentation and line breaks to make JSON human-readable. Minifying removes all unnecessary whitespace to reduce file size, which is ideal for production environments or API responses. Minified JSON loads faster but is harder to read, while formatted JSON is easier to debug but takes up more space.

Can I use this tool for large JSON files?

Yes, the JSON formatter can handle large files efficiently since all processing happens locally in your browser using JavaScript. However, extremely large files (100MB+) may slow down depending on your device's performance. For best results with very large files, use a modern browser like Chrome, Firefox, or Edge.

Why is my JSON invalid?

JSON has strict syntax rules. Common reasons for invalid JSON include: trailing commas after the last item, using single quotes instead of double quotes, unquoted property names, comments (JSON doesn't support comments), undefined or NaN values, and duplicate keys. Our validator will help you identify and fix these issues.

Can I format JSON from an API response?

Absolutely! This is one of the most common use cases. When you receive a minified JSON response from an API, paste it into the formatter to make it readable. This helps you understand the data structure, debug issues, and extract the information you need. Many developers use this tool daily when working with REST APIs.

What is the recommended indentation for JSON?

The most common standard is 2 spaces per indentation level, which is what this tool uses by default. Some teams prefer 4 spaces or tabs, but 2 spaces is widely accepted as it balances readability with file size. The JSON specification itself doesn't mandate any specific indentation.

Can I convert JSON to other formats?

While this tool focuses on formatting and validating JSON, we offer other tools for conversion. You can convert JSON to CSV for spreadsheet use, JSON to YAML for configuration files, or JSON to TypeScript interfaces for type-safe development. Check our related tools section below for these converters.

Does this tool work offline?

Yes! Once the page loads, all formatting, validation, and minification happens in your browser without any internet connection. This makes it perfect for working with sensitive data or in environments with restricted internet access. You can even bookmark the page for quick offline access.