JSON Formatter/Validator

Format, validate, and beautify JSON data. Minify JSON, check syntax errors, and make JSON readable for developers.

What It Does

A JSON Formatter is an essential development tool that beautifies, validates, and formats JSON (JavaScript Object Notation) data. JSON is the most widely used data format for web APIs, configuration files, and data exchange between systems. This formatter takes minified, compressed, or poorly formatted JSON and transforms it into a clean, readable structure with proper indentation and syntax highlighting. It also validates JSON syntax and highlights errors, making it indispensable for developers working with APIs, debugging data structures, or configuring applications.

Key Features:

  • Instant JSON formatting with customizable indentation (2 or 4 spaces, tabs)
  • Real-time syntax validation with detailed error messages and line numbers
  • Syntax highlighting for keys, strings, numbers, booleans, and null values
  • Minification option to compress JSON for production use
  • Tree view for exploring complex nested structures
  • Support for large JSON files (up to several MB)
  • Copy formatted output with a single click
  • Repair common JSON errors automatically (trailing commas, missing quotes)

How To Use

Format and validate your JSON data in seconds. Whether you're debugging an API response or cleaning up a configuration file, our formatter makes JSON readable and error-free.

1

Paste Your JSON

Copy your JSON data from anywhere—API responses, log files, configuration files, or code—and paste it into the input area. The tool accepts both minified and already-formatted JSON.

2

Automatic Validation

The formatter automatically validates your JSON syntax as you type or paste. If there are errors, you'll see clear error messages with line and column numbers pointing to the problem.

3

Choose Formatting Options

Select your preferred indentation style: 2 spaces (compact), 4 spaces (readable), or tabs. You can also choose between formatting (pretty-print) or minifying (compress).

4

View Formatted Output

Instantly see your JSON beautifully formatted with proper indentation, line breaks, and syntax highlighting. Nested objects and arrays are clearly structured for easy reading.

5

Copy or Download

Use the copy button to quickly copy the formatted JSON to your clipboard, or download it as a .json file for saving or sharing with your team.

Pro Tips

  • •Use 2-space indentation for compact JSON in version control
  • •Switch to tree view for exploring deeply nested structures
  • •Minify JSON before sending it over networks to reduce bandwidth
  • •Use the validator to check JSON from unreliable sources before parsing
  • •Format JSON in your clipboard before pasting into code editors
  • •Save frequently used JSON structures as files for quick access

Benefits

Quickly identify and fix syntax errors in JSON data
Make API responses readable during development and debugging
Reduce file size with minification for production deployments
Improve collaboration by sharing well-formatted JSON with team members
Save time by avoiding manual formatting and indentation
Learn JSON structure through visual exploration of formatted data
Validate configuration files before deploying applications
Debug data transformation issues by comparing input and output

Use Cases

API Response Debugging

Format minified API responses to quickly understand the data structure and locate specific fields.

Format a compressed REST API response to find error details

Configuration File Management

Validate and format JSON configuration files for applications, ensuring proper syntax before deployment.

Format package.json, tsconfig.json, or .eslintrc files

Database Export Formatting

Make database JSON exports readable for analysis, migration, or documentation purposes.

Format MongoDB or PostgreSQL JSON dumps

Code Review Preparation

Format JSON files before committing to version control, ensuring consistent styling across the team.

Beautify JSON before git commit for code review

API Documentation

Create clear, readable JSON examples for API documentation and developer guides.

Format request/response examples for Swagger or OpenAPI specs

Data Transformation Testing

Compare input and output JSON when testing data transformation scripts or ETL pipelines.

Validate transformed data structure in data processing workflows

Code Examples

API Response Example

Formatted API response with nested data object

json 
{
  "status": "success",
  "data": {
    "id": 12345,
    "name": "John Doe",
    "email": "john@example.com"
  }
}

Array of Objects

Formatted array structure with multiple objects

json 
[
  {"id": 1, "name": "Item 1"},
  {"id": 2, "name": "Item 2"}
]

Frequently Asked Questions

1 What's the difference between formatting and minifying JSON?
Formatting (also called beautifying or pretty-printing) adds indentation, line breaks, and spacing to make JSON human-readable. This is ideal for development, debugging, and code reviews. Minifying does the opposite—it removes all unnecessary whitespace, line breaks, and indentation to create the most compact representation possible. Minified JSON is smaller in file size, which reduces bandwidth usage and speeds up network transmission, making it ideal for production APIs. Use formatting during development and minification for production.
2 Why is my JSON showing a syntax error?
Common JSON syntax errors include: missing or extra commas between elements, using single quotes instead of double quotes for strings, trailing commas after the last element in arrays or objects, unquoted property names, missing closing brackets or braces, or invalid special characters. JSON is stricter than JavaScript—property names must be in double quotes, and there's no support for comments, trailing commas, or undefined values. Our formatter shows the exact line and position of errors to help you fix them quickly.
3 Can JSON Formatter handle very large files?
Yes, our formatter can handle JSON files several megabytes in size directly in your browser. However, extremely large files (10MB+) may cause performance issues depending on your device. For massive JSON files, consider using command-line tools like jq or formatting in chunks. Browser-based tools like ours are perfect for typical API responses, configuration files, and datasets up to a few thousand lines. All processing happens client-side, so your data never leaves your computer.
4 Is JSON the same as JavaScript objects?
JSON (JavaScript Object Notation) is based on JavaScript object syntax but has stricter rules. Key differences: JSON requires double quotes around property names and string values (JavaScript allows single quotes or no quotes for simple property names); JSON doesn't support trailing commas, comments, undefined values, functions, or dates; and JSON must be valid UTF-8 text. JSON is a data format for exchange between systems, while JavaScript objects are living data structures in code. Use JSON.parse() to convert JSON strings to JavaScript objects and JSON.stringify() to do the reverse.
5 How do I fix common JSON errors automatically?
Our formatter can automatically repair some common JSON errors: adding missing quotes around property names, removing trailing commas (not valid in JSON), and fixing some quote mismatch issues. However, for complex structural errors like missing brackets or braces, you'll need to fix them manually. The validator provides clear error messages with line numbers to guide you. When copying JSON from JavaScript code, remember to replace single quotes with double quotes and remove any trailing commas. For ongoing JSON generation, use JSON.stringify() to ensure valid output.

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