JSON Validator
Validate JSON syntax with clear error messages and line numbers. Browser-only, instant, free.
JSON Validator checks whether your JSON is syntactically valid and pinpoints any errors. ConvertDa's free JSON Validator runs in your browser — paste, click Validate, and see pass/fail with exact line and column numbers when something is wrong.
How to json validator
- 1
Paste your JSON into the input area.
- 2
Click Validate.
- 3
See pass/fail status. If invalid, the error line and column are highlighted.
Frequently asked questions
Does it just check syntax, or schema too?▾
Syntax only. For schema validation use a JSON Schema tool — that's a separate concern.
Are comments allowed?▾
No — standard JSON doesn't allow comments. If your input has // or /* */ they'll be flagged as syntax errors.
Will it tell me WHERE the error is?▾
Yes. The error message includes line and column numbers from the parser.
Does it validate against a JSON Schema?▾
No — only syntax. JSON Schema validation (checking that fields match a defined contract) is a different tool. We may add it later if there's demand.
Can it tell me what's wrong, not just where?▾
Yes. The error message describes the issue (e.g. 'Unexpected token } in JSON at position 47'), and we translate the position into a line and column so you can find it quickly.