JSON Formatter & Validator – Free Online Tool
Format, validate, and beautify your JSON data instantly. Detect syntax errors with precise line numbers. No signup, no ads, completely free.
Formatted JSON will appear here...What is a JSON Formatter?
A JSON Formatter is a tool that takes raw or minified JSON (JavaScript Object Notation) data and restructures it with proper indentation and line breaks, making it human-readable. JSON is the most common data format used in web APIs, configuration files, and data storage.
Our JSON Formatter & Validator not only beautifies your JSON but also validates it against the JSON specification. If your JSON contains syntax errors, the tool will pinpoint the exact location of the error, helping you debug quickly.
Unlike other tools, this formatter runs entirely in your browser. Your sensitive data never leaves your device, ensuring complete privacy and security.
How to Format and Validate JSON Online
Paste Your JSON
Copy your JSON data and paste it into the input area on the left. You can also click "Load Sample" to try with example data.
Click Format
Click the "Format" button to beautify your JSON with 2-space indentation. The formatted output will appear on the right.
Review & Copy
Review the formatted JSON. If there are errors, they'll be highlighted with line numbers. Click "Copy" to copy the result.
Features
Pretty Print JSON
Format JSON with proper indentation and structure for easy reading.
Validate JSON
Instantly detect syntax errors with precise line and column numbers.
Lightning Fast
Client-side processing means your data never leaves your browser.
One-Click Copy
Copy formatted JSON to clipboard with a single click.
Dark & Light Mode
Choose between dark and light themes for comfortable editing.
Fully Responsive
Works seamlessly on desktop, tablet, and mobile devices.
Privacy First
Your JSON data is processed locally. Nothing is sent to any server.
No Limits
Format large JSON files without restrictions or timeouts.
Frequently Asked Questions
What is JSON?
JSON (JavaScript Object Notation) is a lightweight data interchange format that is easy for humans to read and write, and easy for machines to parse and generate. It is based on a subset of JavaScript and is commonly used for transmitting data in web applications between a server and client.
Is this JSON formatter free to use?
Yes, this JSON Formatter & Validator is completely free to use with no limitations. There are no premium features, no signup required, and no advertisements. You can format and validate as much JSON as you need.
Is my data secure when using this tool?
Absolutely. All JSON processing happens directly in your browser using JavaScript. Your data is never sent to any server or stored anywhere. This makes it safe to use with sensitive or confidential JSON data.
What happens if my JSON is invalid?
If your JSON contains syntax errors, the validator will display a clear error message with the line number and column where the error was detected. Common errors include missing commas, unclosed brackets, or invalid characters.
Can I format large JSON files?
Yes, the formatter can handle large JSON files efficiently. Since processing happens in your browser, performance depends on your device's capabilities. For extremely large files (several megabytes), you may experience a brief delay.
What is the difference between Format and Minify?
Format (or beautify) adds proper indentation and line breaks to make JSON readable. Minify does the opposite - it removes all unnecessary whitespace to create the smallest possible JSON string, which is useful for reducing data transfer size.