What is JSON?
JSON (JavaScript Object Notation) is a lightweight data interchange format widely used in web APIs, config files, and data exchange. This free online JSON formatter auto-formats your JSON on paste, and supports auto-repair, YAML/CSV/TypeScript conversion, tree view, and JSONPath queries — all in your browser with no ads.
Format
Beautify compressed JSON with proper indentation for better readability.
Validate
Check if your JSON is syntactically correct and find errors.
Minify
Remove whitespace to reduce file size for production use.
Auto-Repair
Automatically fix common JSON errors like trailing commas, single quotes, comments, and unquoted keys.
YAML/CSV Conversion
Convert JSON data to YAML or CSV format for copying or downloading.
TypeScript Generation
Automatically generate TypeScript interfaces by analyzing JSON structure.
How to Use JSON Formatter
- Paste JSON (Auto-Formats!) — Paste valid JSON and it auto-formats instantly — no button needed!
- Auto-Repair or Format — Use 'Auto-Repair' to fix broken JSON errors, or click 'Format (Beautify)' to apply indentation manually.
- View as Tree — Switch between text/tree view modes to visually explore the data structure.
- Switch View Modes — Explore results in YAML, CSV, or TypeScript view modes.
- Copy or Download — Copy or download the result in your preferred format.
Use Cases
API Development & Testing
Prettify REST API responses to quickly understand data structures and debug issues.
Debugging & Validation
Instantly detect JSON syntax errors and pinpoint the exact location of issues.
Config File Editing
Neatly organize and edit configuration files like package.json and tsconfig.json.
Learning & Data Analysis
Visualize complex JSON structures in tree view to understand data models.
Data Conversion
Convert JSON to YAML or CSV for use in other systems or spreadsheets.
TypeScript Development
Auto-generate TypeScript interfaces from API response JSON for type-safe code.
Frequently Asked Questions
Q. What is JSON?
JSON (JavaScript Object Notation) is a lightweight text-based format for storing and transmitting data. It's easy for humans to read and machines to parse, widely used in web APIs and configuration files.
Q. What is a JSON formatter used for?
It's used to prettify compressed JSON for readability or to find and fix JSON syntax errors. Useful for API response analysis, config file editing, and data validation.
Q. What's the difference between JSON and JavaScript objects?
JSON is a string-based data format, while JavaScript objects are a programming language data type. In JSON, keys must be wrapped in double quotes, and functions or undefined cannot be values.
Q. Is there a maximum file size for JSON?
JSON itself has no size limit, but this tool runs in the browser, so it works best with data within a few MB. For very large files, consider using a dedicated editor.
Q. Why use Minify?
Minify removes unnecessary whitespace and line breaks from JSON files to reduce file size. This improves transfer speed and saves storage when deploying API responses or configuration files.
Q. What errors can JSON auto-repair fix?
Auto-repair can fix trailing commas, single quotes, JavaScript comments (// and /* */), and unquoted keys - the most common JSON syntax errors.
Q. Can I convert JSON to TypeScript interfaces?
Yes, the TypeScript view automatically generates interfaces from your JSON data, including support for nested objects, arrays, optional fields, and union types.
Q. Does JSON auto-format when I paste it?
Yes! If you paste valid JSON, it automatically formats it for you — no need to click any button. The formatted result appears instantly in the output panel.
Q. How do I make JSON look pretty / readable?
Paste your JSON into the input field and it will auto-format instantly. You can also click the 'Format' button to apply indentation. Switch to Tree view for a visual, collapsible hierarchy of your data.
Privacy Notice
This JSON formatter processes all data entirely within your browser. Your JSON data is never sent to any server, and no information is stored or collected. You can safely process sensitive data with complete confidence.