JSON Validator

Validate JSON and Find Errors Fast

The JSON Validator checks whether your JSON is syntactically correct and, when it is not, points you straight to the line and column where parsing failed. A single missing comma, an unquoted key, or a stray trailing bracket can break an entire config or API request — this tool surfaces those problems immediately instead of leaving you to hunt through a wall of text.

How it works

Validation happens locally in your browser using the same kind of parser your JavaScript runtime uses. Paste your data and it is parsed on your device; if an error is found, the message tells you what went wrong and where. Nothing is uploaded, so validation is instant and works even without a connection.

Practical uses

• Confirm an API response is well-formed before writing code against it.
• Catch syntax mistakes in config files before you deploy.
• Verify hand-edited JSON fixtures used in tests.
• Debug payloads that a service keeps rejecting.

Once your JSON is valid, the JSON Formatter makes it easy to read and the JSON Minifier compresses it for production. If you are decoding tokens, the JWT Decoder reads the JSON claims inside a JWT.

Private by design

Because validation runs entirely client-side, your JSON — including any secrets it carries — never leaves your browser. There is no sign-up and no server involved at any point.