Format, validate, and beautify JSON data with syntax highlighting. Detect errors, format for readability, or minify for production.
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Enter JSON and click "Format JSON" to see results
Auto-indent and beautify JSON for better readability and debugging.
Real-time error detection with detailed error messages and line numbers.
Compress JSON for production use, reducing file size and bandwidth.
One-click copying for seamless integration into your workflow.
All processing happens locally - your data never leaves your browser.
Works perfectly on desktop, tablet, and mobile devices.
JSON (JavaScript Object Notation) is a lightweight, text-based data interchange format. Despite its name, JSON is language-independent and used across virtually all modern programming languages.
API responses, configuration files, data storage, message passing between services, AJAX requests, NoSQL databases, and mobile app data exchange.
JSON is the standard format for REST API communication, used for both request and response bodies.
Package.json files define Node.js project dependencies, scripts, and metadata using JSON format.
Many tools use JSON for configuration: tsconfig.json, .eslintrc.json, settings files.
NoSQL databases like MongoDB store documents in JSON-like format (BSON). localStorage also uses JSON.
Modern JavaScript uses JSON for asynchronous data exchange with servers via fetch API.
Mobile apps use JSON for API communication, local storage, and configuration across iOS, Android, and React Native.
JSON Schema provides a powerful way to validate the structure, data types, and constraints of JSON documents.
{
"type": "object",
"properties": {
"name": {"type": "string", "minLength": 1},
"age": {"type": "integer", "minimum": 0},
"email": {"type": "string", "format": "email"}
},
"required": ["name", "email"]
}Query JSON documents using XPath-like syntax:
Powerful command-line JSON processor:
Standard format for describing changes to JSON documents:
A: JSON.parse() is safer as it only parses valid JSON and won't execute code. eval() can execute any JavaScript, making it a security risk. Always use JSON.parse() for JSON data and handle parsing errors with try-catch blocks.
A: No, standard JSON doesn't support comments. However, some parsers support JSON with comments (JSONC), and tools like JSON5 extend JSON to include comments, trailing commas, and other JavaScript-like features.
A: For large files, use streaming parsers instead of loading the entire file into memory. Consider pagination for APIs, compression (gzip), and tools like JSONStream for Node.js or streaming fetch responses in browsers.
A: Common causes include trailing commas, single quotes instead of double quotes, missing quotes around property names, or trying to parse HTML/text as JSON. Use a JSON validator to identify the exact syntax error location.
A: JSON doesn't have a native date type. Use ISO 8601 string format (2023-12-25T10:30:00Z) for dates, or Unix timestamps for simple cases. Parse these back to Date objects in your application code.
A: Yes, for API responses and large data files. Minifying removes whitespace, reducing bandwidth usage. However, use HTTP compression (gzip/brotli) which is more effective. Keep formatted JSON for development and debugging purposes.
A: Use JSON Schema libraries like Ajv (JavaScript), jsonschema (Python), or built-in validation in many frameworks. Define your schema once and validate both client and server-side for consistency.
A: There's no official size limit, but practical limits include memory constraints, server payload limits (often 1-50MB), and browser limits. For large datasets, consider pagination, streaming, or alternative formats like Protocol Buffers.