JSON Formatter & Beautifier

When Do You Need JSON Formatting?

JSON is frequently minified for transmission — all whitespace removed to save bytes. While compact JSON is efficient for APIs and storage, it is nearly unreadable for humans. This formatter adds consistent indentation and line breaks so you can scan keys, spot nesting levels, and understand the structure at a glance.

Common Use Cases

API responses: Copy the raw response body from your browser developer tools or Postman and paste it here to read it clearly, especially for deeply nested payloads.

Config files: Application config files stored as JSON (like package.json, tsconfig.json, or appsettings.json) are easier to review and edit when formatted.

Debugging: When a JSON parse error occurs in your application, paste the offending string here to see the formatted structure and locate the syntax error visually.

Minifying for production: Use the Minify button to strip all whitespace from formatted JSON before embedding it in code or sending it in a request.

Common JSON Syntax Errors

Trailing commas: JSON does not allow a comma after the last item in an array or object. {"a":1,} is invalid — remove the trailing comma.

Single quotes: All strings — including keys — must use double quotes. {'key': 'value'} is invalid JavaScript object notation, not JSON.

Unquoted keys: Object keys must be quoted strings. {key: "value"} is not valid JSON even though it works in JavaScript.

Comments: JSON does not support comments. Lines starting with // or /* ... */ blocks will cause a parse error.

Undefined and NaN: JSON has no undefined or NaN values. Use null for missing values and represent non-finite numbers as strings.

Need more encoding tools? Try the full Encode & Decode suite.