JSON Validator

Quickly check if your JSON data is structurally valid. Errors are reported instantly as you paste or type.

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Paste your JSON data below to validate it.

What is JSON Validation?

JSON validation is the process of checking whether a given string of text conforms to the official JSON (JavaScript Object Notation) syntax rules. Because JSON is strictly typed, even a single missing quote or misplaced comma will cause parsers in JavaScript, Python, or other languages to throw a fatal error.

This tool uses the native browser JSON.parse() API to immediately catch and display these errors as you type, helping you fix broken configuration files or API responses before deploying them to production.

Common JSON Syntax Errors

  • Trailing Commas: Unlike standard JavaScript objects, JSON does not allow a comma after the last item in an array or object. (e.g., [1, 2,] is invalid).
  • Single Quotes: JSON requires double quotes (") around all property keys and string values. Single quotes (') or backticks (\`) will throw a syntax error.
  • Missing Quotes on Keys: Every property name must be wrapped in double quotes. { name: "John" } is invalid; it must be { "name": "John" }.
  • Comments: The JSON specification does not support comments (like // or /* */). All text must be valid data.