Is this JSON formatter free to use?
Yes, this JSON formatter is completely free with no usage limits, no signup required, and no ads blocking the tool.
Free Online JSON Formatter & Validator
This JSON formatter online tool helps you format, validate, and fix JSON data directly in your browser. Whether you are debugging API responses or cleaning up configuration files, paste your JSON below and get properly formatted output in seconds.
Built for developers, API testers, and anyone working with structured data. All processing happens client-side — your data is never uploaded or stored on any server.
What is JSON?
JSON (JavaScript Object Notation) is a lightweight data format used to exchange information between servers and web applications. It is human-readable, easy to parse, and supported by virtually every programming language.
JSON structures data using key-value pairs and arrays. It has become the standard format for REST APIs, configuration files, and data storage in modern web development.
Why Format JSON?
Raw JSON from APIs or logs is often minified or poorly indented, making it difficult to read and debug. Formatting adds proper indentation and line breaks so you can quickly understand the data structure.
Formatted JSON helps you spot missing brackets, incorrect nesting, and other structural issues. It is essential when working with complex nested objects or troubleshooting API responses.
Common JSON Errors
Trailing Commas
JSON does not allow commas after the last item in arrays or objects. This formatter automatically removes them.
Single Quotes
JSON requires double quotes for strings and keys. Single quotes cause parse errors. This tool converts them automatically.
Unquoted Keys
In JavaScript, object keys can be unquoted. In JSON, all keys must be wrapped in double quotes.
Invalid Values
JSON only supports strings, numbers, booleans (true/false), null, arrays, and objects. Functions, undefined, and comments are not valid.
Client-Side Processing & Privacy
This JSON formatter processes everything in your browser using JavaScript. Your data never leaves your device and is not sent to any server.
This makes it safe to use with sensitive data, API keys, and proprietary information. There is no logging, no storage, and no network requests during processing.
How to Format JSON Online
1
Paste JSON
Paste your JSON into the editor above
2
Format
Click Format to beautify your JSON
3
Fix Errors
Errors are highlighted and auto-fixed
4
Copy or Download
Copy to clipboard or download the file
Frequently Asked Questions
Is my JSON data secure?
Absolutely. All processing happens in your browser using JavaScript. Your JSON data is never uploaded to any server or stored anywhere.
Can this tool handle large JSON files?
Yes, this formatter can handle files up to 10MB or more. Processing happens locally in your browser, so performance depends on your device.
Can it fix invalid JSON?
Yes. The tool automatically fixes common issues like trailing commas, single quotes, unquoted keys, and Python-style booleans (True/False/None).
What is the difference between beautify and minify?
Beautify adds indentation and line breaks for readability. Minify removes all whitespace to create the smallest possible file size.
Does it work in all browsers?
Yes. This tool works in Chrome, Firefox, Safari, Edge, and other modern browsers. No plugins or extensions required.
Related Resources
Visit our JSON Formatter homepage for additional tools including JSON to YAML conversion, tree viewer, and schema validation.
Learn more about JSON syntax in our guide: Why Trailing Commas Are Invalid in JSON (RFC 8259).