JSON Validator
Check JSON syntax and get the exact line and column for any error. Runs in your browser.
Paste any text and the validator runs JSON.parse()on it. If parsing succeeds, the input is valid JSON and the output shows a green confirmation. If it fails, you'll see the exact line and column of the first error. All checking happens in your browser via JavaScript.
What does 'Unexpected token' mean?
It means the parser found a character it didn't expect at that position. Common causes are missing commas between properties, missing closing braces, or unquoted keys.
Does this check JSON Schema?
No. This validates JSON syntax (well-formedness) only — not whether the data matches a schema. JSON Schema validation is a separate tool.
What's the difference between valid and well-formed JSON?
In practice, the same thing. Valid JSON is parseable by JSON.parse(). 'Well-formed' is sometimes used to mean syntactically correct.