Free JSON Formatter & Validator Online
Instantly beautify, validate, and minify JSON with syntax highlighting, error detection, and JSONC support. Process API responses, config files, and data structures with 100% browser-based privacy.
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› About this tool · FAQ
Stop squinting at minified JSON! Format and validate JSON instantly with automatic error detection, syntax highlighting, and pretty printing. Catches missing quotes, trailing commas, and invalid syntax. Works with JSON and JSONC. Perfect for debugging API responses and config files. Free, works offline, unlimited usage.
How do I format JSON online?
Paste your JSON into the formatter, choose indentation settings (2 or 4 spaces), and click Format. The tool beautifies minified JSON instantly with proper structure, syntax highlighting, and error detection for readable output.
Is this JSON formatter free?
Yes, completely free with no limits on usage. No signup required, no watermarks. All formatting happens in your browser for complete privacy and unlimited JSON beautification.
Are my JSON files uploaded to servers?
No, all JSON formatting and validation happens locally in your browser. Your data never leaves your computer, ensuring complete privacy for sensitive API responses and configuration files.
How to get specific values from JSON?
Use our JSON formatter to make your data readable, then easily locate and extract the values you need. The formatted structure makes it simple to navigate through nested objects and arrays to get exactly what you're looking for.
How to search through JSON data?
Format your JSON first to create a readable structure. This makes it easy to search for specific keys, values, or patterns in your data. Use browser search (Ctrl+F) on the formatted output to quickly find what you need.
How to extract nested JSON objects?
Our formatter reveals the complete structure of nested JSON objects with proper indentation. This makes it easy to identify and extract specific nested data, whether it's user profiles, configuration settings, or API response data.
What is JSON parsing and how does it work?
JSON parsing converts JSON text into a structured format your applications can understand. Our tool parses JSON/JSONC input, validates the syntax, and outputs clean, properly formatted JSON that's ready for use in any application.
Understanding JSON file format structure
JSON (JavaScript Object Notation) uses key-value pairs, arrays, and nested objects. Our formatter shows the exact structure with proper indentation, making it easy to understand the hierarchy and relationships in your JSON data.
Is my JSON data secure when using this tool?
Yes, all processing happens locally in your browser. No data is sent to any server or stored anywhere.
Can I format large JSON files?
Yes, but very large files (>10MB) might slow down your browser. Consider breaking them into smaller chunks if needed.
Can I minify JSON as well as format it?
Yes, set the indent to 0 to create minified (compact) JSON output.
How do I pretty print JSON online?
Simply paste your JSON into the formatter and click "Format JSON". The tool will automatically pretty print your JSON with proper indentation, making it readable and well-structured.
Can I validate JSON syntax errors online?
Yes, our JSON validator automatically detects syntax errors, missing quotes, unclosed brackets, trailing commas, and other common JSON formatting issues with detailed error messages and line numbers.
How do I fix "Unexpected token" JSON errors?
Unexpected token errors usually mean missing quotes around strings, extra commas, or invalid characters. Our validator highlights the exact location and suggests fixes for these common JSON syntax problems.
Can I convert minified JSON to readable format?
Absolutely! Paste your minified (compressed) JSON and our formatter will expand it into a readable, properly indented format with clear structure and hierarchy.
Does this tool work with JSON API responses?
Yes, perfect for formatting API responses from REST APIs, GraphQL, or any web service. Copy API response JSON directly from your browser network tab or API client and format it instantly.
How do I sort JSON keys alphabetically?
Enable the "Sort keys alphabetically" option in the formatting settings. This will reorganize all object properties in alphabetical order, making JSON data easier to compare and analyze.
Can I remove comments from JSONC files?
Yes, the tool automatically removes both single-line (//) and multi-line (/* */) comments from JSONC (JSON with Comments) files, converting them to valid JSON format.
What's the maximum JSON file size supported?
The tool can handle JSON files up to 10MB efficiently. Larger files may work but could slow down your browser. For very large datasets, consider splitting them into smaller files.
How do I download formatted JSON?
After formatting your JSON, click the "Download" button to save the formatted result as a .json file, or use "Copy" to copy the formatted JSON to your clipboard for pasting elsewhere.
What is the difference between JSON and JSONC?
Standard JSON follows strict RFC 8259 specifications with no comments allowed. JSONC (JSON with Comments) is an extension that supports single-line (//) and multi-line (/* */) comments, trailing commas, and is commonly used in configuration files like VS Code settings. Our formatter handles both formats seamlessly.
How do I fix "Unexpected end of JSON input" error?
This error typically means your JSON is truncated or has unmatched brackets. Check that all opening braces { and brackets [ have corresponding closing characters } and ]. Our validator highlights the exact position where the JSON structure becomes invalid.
Can I format JSON from API responses?
Absolutely! Copy the raw JSON response from browser DevTools Network tab, Postman, or any API client and paste it directly into our formatter. We support all standard API response formats including nested objects, arrays, and mixed data types.
How do I handle special characters in JSON strings?
Special characters must be escaped with backslashes: use \n for newlines, \t for tabs, \\ for backslashes, and \" for quotes within strings. Our formatter automatically handles Unicode characters and can optionally convert them to \uXXXX escape sequences for compatibility.
What causes "Duplicate key" warnings in JSON?
Duplicate keys occur when the same property name appears multiple times in an object. While technically valid JSON, most parsers only keep the last value, causing data loss. Our formatter detects and warns about duplicate keys so you can fix them before processing.
How do I convert JSON to other formats?
After formatting your JSON, you can use our related tools to convert it to XML, YAML, CSV, or other formats. Check the related tools section for JSON to XML Converter, JSON to CSV Converter, and YAML Formatter for seamless data transformation.
Does the formatter work offline?
Yes! Once the page loads, all JSON formatting and validation works entirely offline. Your data never leaves your browser, making it perfect for working with sensitive configuration files, API keys, or proprietary data structures without internet connectivity.
How do I validate JSON schema compliance?
While our formatter validates JSON syntax, for JSON Schema validation (checking if data matches a specific structure), you would need a dedicated JSON Schema validator. Our tool focuses on syntax validation and formatting rather than schema compliance checking.
Can I use this formatter in my development workflow?
Yes! Use our JSON formatter for quick formatting during development, debugging API responses, cleaning up configuration files, or preparing JSON data for documentation. The tool is designed for repeated use with no rate limits or registration required.