JSON Validator
This JSON validator checks whether a JSON string is syntactically correct according to the JSON specification. If parsing fails, it returns a human-readable error message along with the exact line and column of the problem, so you can fix it without guessing. Validation happens entirely in your browser — nothing you paste is uploaded or stored.
Frequently asked questions
What does a JSON validator check?
A JSON validator parses your text against the JSON syntax specification and reports whether it is well-formed, catching problems like mismatched brackets, trailing commas, and unquoted keys.
What are the most common JSON syntax errors?
The most frequent errors are trailing commas after the last item, unquoted object keys, single quotes used for strings, comments, and mismatched or missing brackets — strict JSON forbids all of these.
Does this tool validate against a JSON Schema?
No, it only checks syntax — whether the text is parseable JSON. Validating structure and data types against a JSON Schema is a separate kind of check this tool does not perform.
Where exactly does it show the error location?
On invalid input, the validator reports the line and column number where parsing failed, along with a plain-language description of what went wrong, so you can jump directly to the problem instead of scanning the whole document.
Is my data sent anywhere when I validate it?
No. Validation runs entirely client-side in your browser, so the JSON you paste is never uploaded, logged, or transmitted to a server.
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