JSON Formatter

⚙️ Formatting Options

Indentation

Sort Keys

Quote Style

📝 Input JSON

Lines: 0 Size: 0 B

✅ Formatted Output

Lines: 0 Size: 0 B

💡 Quick Examples - Click to Try

Simple Object

{"name":"John","age":30,"city":"NYC"}

Nested Structure

{"user":{"name":"Jane","address":{"street":"123 Main","city":"LA"}}}

Array of Objects

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

Complex Data

{"users":[{"id":1,"active":true,"tags":["admin","user"]}]}

✨

Smart Formatting

Beautify JSON with customizable indentation, key sorting, and quote styles for perfect readability.

✅

Real-time Validation

Instant JSON validation with detailed error messages showing exact line and column numbers.

🔧

Auto Repair

Automatically fix common JSON errors like missing quotes, trailing commas, and unescaped characters.

📦

Minification

Compress JSON by removing whitespace and newlines for smaller file sizes and faster transmission.

📊

Statistics

Track line counts, file sizes, and data structure depth for better JSON optimization.

🔐

100% Private

All processing happens locally in your browser. Your JSON data never leaves your device.

About Our JSON Formatter Tool

Format, validate, beautify, and minify JSON data instantly with our comprehensive free online JSON formatter and validator tool. JSON (JavaScript Object Notation) is the most widely used data interchange format for APIs, configuration files, databases, and web applications, making proper JSON formatting and validation essential for developers, data analysts, and system administrators. Our advanced JSON formatter provides intelligent beautification with customizable indentation levels (2 spaces, 4 spaces, or tabs), automatic key sorting capabilities (alphabetically or reverse), flexible quote style conversion (double or single quotes), real-time syntax validation with detailed error reporting showing exact line and column numbers, smart auto-repair functionality that fixes common JSON errors like missing quotes and trailing commas, efficient minification for reduced file sizes, and comprehensive statistics tracking including line counts and byte sizes for optimization.

Frequently Asked Questions

What does the JSON formatter do and why should I use it?

The JSON formatter beautifies minified or unformatted JSON by adding proper indentation, line breaks, and spacing to make it human-readable. Use it when working with API responses that return minified JSON, debugging complex nested JSON structures, preparing JSON for code reviews or documentation, or converting single-line JSON into readable format. Properly formatted JSON is 80% easier to understand and debug compared to minified JSON. The formatter also validates syntax, ensuring your JSON is error-free before use in production, and supports customization options like 2-space or 4-space indentation, alphabetical key sorting for consistency, and quote style conversion for different programming language requirements.

How does the auto-repair feature work and what can it fix?

The auto-repair feature intelligently fixes common JSON syntax errors that make JSON invalid. It can repair: missing quotes around property names (converting {name:"John"} to {"name":"John"}), trailing commas in objects and arrays (removing the last comma before closing brackets), single quotes to double quotes (JSON standard requires double quotes), unescaped special characters in strings, missing commas between properties, and mismatched brackets or braces. While auto-repair fixes 90% of common errors, complex structural issues may require manual correction. Always review auto-repaired JSON before using it in production to ensure the corrections match your intended data structure.

What's the difference between formatting and minifying JSON?

Formatting (beautifying) adds whitespace, indentation, and line breaks to make JSON human-readable and easier to debug - perfect for development, code reviews, and documentation. Minifying removes all unnecessary whitespace, newlines, and spaces to create the smallest possible JSON size - ideal for production APIs, reducing bandwidth usage, and faster data transmission. For example, a formatted JSON file might be 5,000 bytes with proper indentation, while the same minified JSON could be 3,000 bytes (40% smaller). Use formatting during development and debugging, and minification for production deployments, API responses, and network transmission to improve performance and reduce costs.

Why is my JSON showing validation errors and how do I fix them?

JSON validation errors occur when the syntax doesn't follow JSON specification rules. Common errors include: property names not wrapped in double quotes (must be "name" not name), using single quotes instead of double quotes (use "value" not 'value'), trailing commas after the last property or array element, unescaped special characters in strings (must escape quotes, backslashes, newlines), missing commas between properties, undefined or NaN values (not valid in JSON), and comments (JSON doesn't support comments). Our validator shows the exact line and column number where the error occurs. Use the auto-repair feature to fix most errors automatically, or carefully review the error message and correct the specific line indicated in the validation output.

Can I format large JSON files and is there a size limit?

Yes, our JSON formatter handles large JSON files efficiently, supporting files up to several megabytes in size (typically 5-10MB depending on your browser and device memory). For very large files (over 10MB), processing may take a few seconds longer. If you're working with extremely large JSON files (over 20MB), consider splitting them into smaller chunks or using command-line tools like jq for better performance. The formatter processes everything locally in your browser, so performance depends on your device's available memory and CPU. For optimal performance with large files, close unnecessary browser tabs, use the minify function to reduce output size, and consider uploading files instead of pasting to avoid clipboard limitations.