What is Format JSON Online?

Format JSON Online is a free, browser-based JSON toolkit that formats, validates, and minifies JSON data. It includes 60+ tools for JSON manipulation, conversion to 15+ formats, and AI-powered error fixing. All processing runs client-side for privacy, supporting files up to 100MB.

JSON (JavaScript Object Notation) is a lightweight data interchange format that's easy for humans to read and write. It’s language-independent and widely used for data exchange between servers and web applications.

{
  "name": "John Doe",
  "age": 30,
  "isStudent": false,
  "courses": ["Math", "Science"],
  "address": {
    "street": "123 Main St",
    "city": "Boston"
  }
}

👉 For a complete overview, see our full Guide to JSON

Yes, Format JSON Online is 100% free with no usage limits, no registration required, and no hidden costs. All 60+ tools including the JSON formatter, validator, minifier, and converters are freely accessible without payment.

FormatJSONOnline offers an all-in-one JSON toolkit that combines essential tools in a single interface: JSON Formatter to beautify your data, JSON Validator with AI-powered error fixing, JSON Minifier to compress for production, and a comprehensive editor with advanced features. Plus dozens of specialized converters and utilities for 15+ formats.

Format JSON Online can process JSON files up to 100MB in size. The tool uses Web Workers for client-side processing, handling large files efficiently without blocking your browser or sending data to external servers.

Yes, all core processing happens entirely in your browser using client-side JavaScript. Your JSON data never leaves your device or gets sent to servers except when using optional AI features, which process data securely without storage.

No, all our tools are freely available without requiring any registration or account creation. You can use them immediately without any login or signup process. However, creating an account would allow you to save your work and access additional features.

To format JSON, simply paste your JSON data into our formatter tool, select your preferred indentation size (2-8 spaces or tabs), choose formatting options like quote style and key sorting, then click 'Format JSON'. The tool will automatically format your JSON with proper indentation, line breaks, and syntax highlighting.

JSON files can be opened in any text editor like Notepad, VS Code, or Sublime Text. For viewing and editing with our tools, you can either upload the file directly using the upload button, drag and drop it into the input area, or copy and paste its contents. You can also convert JSON files to Excel, CSV, or other formats using our conversion tools.

Yes! Our URL sharing feature allows you to generate shareable links for your JSON data. The data is compressed and encoded in the URL, so recipients can view your formatted JSON without you having to send files. You can also generate QR codes for easy mobile sharing and password protection for sensitive data.

Our AI-powered JSON validator can automatically detect and fix common JSON syntax errors like missing quotes, trailing commas, incorrect brackets, and more. When validation fails, simply click the 'Fix with AI' button and our intelligent system will attempt to correct the errors and provide a valid JSON output.

JSON often becomes invalid due to common syntax errors: missing keys quotes, trailing commas (not allowed in standard JSON), unclosed brackets or braces, or extra whitespace in wrong places. Our Validator identifies the exact line number of your error, and our AI Fixer can repair it instantly.

JSON formatting (beautifying) adds whitespace, indentation, and newlines to make JSON human-readable. JSON minifying removes all unnecessary whitespace to minimize file size for production use, reducing bandwidth and storage requirements.

The Chrome extension and VS Code extension versions of Format JSON Online work offline for core formatting, validation, and minification features. The web version requires an internet connection, but all processing still happens locally in your browser.

Format JSON Online converts JSON to and from 15+ formats including: XML, YAML, CSV, Excel, SQL, Python dictionaries, C# classes, TypeScript interfaces, HTML tables, TOON (Token-Oriented Object Notation), and more. Two-way conversion is supported for most formats.