JSON Formatter
Format, minify, validate, and view JSON as a tree. Ideal for API inspection, config editing, and debugging. Supports files up to 1 MB with real-time error detection by line and column.
Last updated:
How to Use
Expand how to useCollapse how to use
- 1
Enter your JSON
Type or paste your JSON data into the text area above.
- 2
Choose format or minify
Click 'Format' for readable indented output, or 'Minify' to remove whitespace and compress.
- 3
Review and copy
Review the formatted JSON and click 'Copy' to copy to clipboard. Use Tree View to visually explore the structure.
JSON Input
Formatted Output
Please enter JSONAbout JSON Formatter
JSON Formatter beautifies, minifies, and validates JSON data in your browser. Paste minified API responses, compact webhook payloads, or dense configuration files and get properly indented, syntax-highlighted JSON in one click. Choose from 2-space, 4-space, or tab indentation to match your project's style. Real-time validation catches syntax errors and pinpoints the exact line and column number, saving you from hunting through hundreds of lines manually. A tree view lets you visually explore nested structures with expand/collapse controls, and minify mode compresses JSON by removing all whitespace for embedding in code or reducing payload size. Handles files up to 1 MB.
Key Features
- Choose indentation style (2 spaces/4 spaces/tabs) for readable formatting
- Minify to remove whitespace and newlines, reducing file size
- Real-time JSON syntax validation with error location (line and column numbers)
- Tree view for visual exploration with expand/collapse functionality
- Handles large JSON files up to 1MB
Common Use Cases
- Format API responses from REST or GraphQL endpoints
- Validate and beautify package.json, tsconfig.json, or .eslintrc
- Debug webhook payloads from Stripe, GitHub, or Slack
- Minify JSON for storage optimization or API requests
- Explore deeply nested JSON with interactive tree view
Frequently Asked Questions
Is my JSON data private?
Yes. All formatting and validation happens entirely in your browser using JavaScript. Your data is never sent to any server, making it safe to paste API keys, authentication tokens, database connection strings, or any sensitive configuration you would not want transmitted to an external service.
What's the maximum file size?
Up to 1 MB (roughly 1 million characters). For most API responses, config files, and webhook payloads this is more than sufficient. For larger files — such as full database exports or bulk data dumps — consider splitting them into smaller chunks or using a CLI tool like jq, which processes files of any size.
Can I validate JSON syntax?
Yes. The tool validates JSON in real time and shows the exact line and column number of any syntax error. The most common mistakes are trailing commas (not allowed in JSON, unlike JavaScript), single-quoted strings (JSON requires double quotes), unescaped special characters inside strings, and missing commas between object properties or array elements.
What indentation options are available?
Choose between 2 spaces, 4 spaces, or tabs. The default is 2 spaces, which matches most JavaScript and TypeScript style guides (Prettier, ESLint recommended). Use 4 spaces if your project follows Python or Java conventions, or tabs if your editor is configured to display tabs at your preferred width.
What's the difference between Format and Minify?
Format adds indentation, line breaks, and consistent spacing to make JSON human-readable. Minify removes all unnecessary whitespace and line breaks, reducing the byte size as much as possible. Minified JSON is useful for embedding in source code, storing in databases, or reducing the size of API request bodies. Format is better for reading, editing, and reviewing.
How do I use the tree view?
Switch to Tree View to browse JSON as a collapsible hierarchy of nodes. Each object and array can be expanded or collapsed independently. This is especially useful for deeply nested structures — such as Kubernetes manifests, AWS CloudFormation templates, or OpenAPI specs — where scrolling through raw text makes it hard to understand the overall shape of the data.
Can I use this tool to fix common JSON errors?
The validator highlights exactly where a syntax error occurs, but automatic correction is not performed — JSON has no safe way to auto-fix ambiguous errors like a missing comma that could belong to either the preceding or following line. Use the error message (line and column) to navigate to the problem, fix it manually, and the tool will immediately confirm when the JSON is valid.