JSON Formatter API — Format, Validate, and Pretty-Print JSON
Format, validate, and pretty-print JSON data with customizable indentation. Instant JSON formatting for developers. Free API.
What is JSON Formatting?
JSON formatting (also called pretty-printing or beautifying) takes minified or poorly formatted JSON and reformats it with proper indentation, line breaks, and spacing. The JSON formatter also validates that the input is valid JSON and reports syntax errors. Supports customizable indentation (spaces or tabs).
How to Use It
Call GET /api/v1/json-formatter?input=%7B%22a%22:1%7D. Returns { formatted: string, valid: boolean, error: string | null, original_size: number, formatted_size: number }.
Try it live
Test this endpoint in the interactive console
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Frequently Asked Questions
What indentation options are available?
Default is 2-space indentation. You can customize with spaces or tabs for different formatting preferences.