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JSON Formatter & Validator
Beautify, minify, and validate JSON payloads. Errors come directly from your browser's native JavaScript parser, matching what your code experiences at runtime.
Input JSON
Indent:
Output
The four errors that cause most invalid JSON
01
Trailing Commas
Legal in modern JavaScript, strictly forbidden in JSON. A comma after the final object property or array element breaks every spec parser.
02
Single Quotes
JSON mandates double quotes around both property keys and string values. Code copied from JS or Python frequently trips on this rule.
03
Unescaped Characters
Literal newlines, unescaped double quotes, or tabs inside string values will cause immediate syntax exceptions.
04
Comments
JSON has no comment syntax. Formats like JSONC or JSON5 are separate extensions and fail strict standard JSON parsers.