JSON Formatter & Validator
Format, beautify, validate, and minify JSON data online. Includes tree view, error detection with line numbers, and indentation options. Free and client-side.
Why use a JSON Formatter?
JSON (JavaScript Object Notation) is the most common data interchange format on the web. However, minified or poorly formatted JSON is difficult to read and debug. A JSON formatter beautifies your data with proper indentation, validates the structure, and highlights errors with exact line and column numbers, making development and debugging much faster.
Key Features
- Format and beautify JSON with configurable indentation
- Validate JSON with detailed error messages and line numbers
- Tree view for exploring JSON structure visually
How to use
- Paste your JSON data in the input field
- Click Format to beautify or Minify to compress
- Copy the result or explore the tree view
Technical Details
Our JSON formatter uses the browser's native JSON.parse() for validation and JSON.stringify() with indentation for formatting. Error positions are calculated by tracking character offsets and converting them to line/column numbers. The tree view recursively renders the parsed JSON structure with color-coded types.
FAQ
What JSON formats are supported?
We support standard JSON including objects, arrays, strings, numbers, booleans, and null values. We also handle nested structures of any depth.
Is my JSON data sent to any server?
No, all processing happens entirely in your browser. Your JSON data never leaves your device.
Related articles
JSON: How to Validate, Format, and Not Break It
The five most common JSON mistakes that make parsers complain, how pretty-printed output differs from minified, and how to pull a field out of a big object.
How to Convert CSV to JSON Without Losing Data Along the Way
Does an Excel export turn to mush when converted? Delimiters, quotes, leading zeros in SKUs and other CSV traps — and how to get your data into JSON in a minute.
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