EN | CS

JSON Formatter & Validator - Format, Validate and Beautify JSON

Free online JSON formatter to format, validate and beautify JSON data instantly. Pretty print JSON, minify JSON, and validate JSON syntax with tree view and error detection.

Input JSON
Output
Formatted JSON will appear here...

About JSON Formatter

Our JSON Formatter is a free, client-side tool that helps developers format, validate, beautify, and minify JSON data instantly. Whether you're debugging API responses, editing configuration files, or working with complex data structures, this tool provides instant feedback and clear error reporting.

Key Features

All processing happens entirely in your browser. Your data never leaves your device, making this tool safe for sensitive information.

Common Use Cases

FAQ

Is my JSON data sent to a server?
No. All formatting and validation happens entirely in your browser. Your data never leaves your device.
What's the maximum JSON size I can format?
There's no hard limit set by the tool, but very large files (tens of MB) may slow down your browser.
Does this tool support JSON with comments?
No, this tool follows standard JSON specification which does not allow comments. Remove comments before formatting.
How does the tree view work?
The tree view renders your JSON as a collapsible hierarchy. Click the toggle buttons to expand or collapse nodes.
How to validate JSON?
Paste your JSON into the input field and click the Validate button. The tool checks for correct syntax including matching braces, quotes, commas, and proper data types. Any errors will be displayed with line and position information.
How to minify JSON?
Click the Minify button to remove all unnecessary whitespace and line breaks from your JSON. This reduces file size for production use or API responses. The minified output is compact but still valid JSON.
How to format JSON?
Paste your JSON into the input field and click the Format button. The tool will beautify your JSON with proper indentation, making it readable and easy to inspect. You can also toggle the tree view for a collapsible hierarchical representation.
What is JSON validation?
JSON validation checks if your JSON data follows the correct syntax according to the JSON specification. It ensures proper structure with matching brackets, quotes, commas, and valid data types. Use the Validate button to check for syntax errors and get detailed error messages.

Related Tools

🔐 Base64 Encoder
Encode and decode Base64 strings and files
🔗 URL Encoder
Encode and decode URLs and components
🔍 Regex Tester
Test and debug regular expressions
⚡ Text Diff
Compare two text blocks line by line