Paste or upload your JSON data
Click Format, Minify, or Validate
Copy or download the result
Paste a raw JSON API response to pretty-print it and quickly understand its structure.
Catch syntax errors in JSON config files, package.json, or API response payloads before they cause runtime errors.
Remove all whitespace from JSON to reduce payload size in API responses and configuration files.
Use the collapsible tree view to navigate deeply nested JSON structures without getting lost.
Pretty-print JSON examples with consistent indentation for use in technical documentation or READMEs.
No. All formatting and validation is done in your browser using JavaScript's JSON.parse. Your data never leaves your device.
The tool uses JavaScript's native JSON parser which is compliant with ECMA-404 (the JSON Data Interchange Standard).
Common causes: trailing commas (not valid in JSON), single quotes instead of double quotes, unquoted keys, or missing commas between elements.
No hard limit. Very large JSON (tens of MB) may slow the browser's rendering, but parsing still works.
Standard JSON does not support comments. If your JSON has // or /* */ comments, remove them first or use JSON5 instead.