JSON Validator Online
Instantly validate JSON syntax and find errors with exact line and column numbers. Private and free.
Output will appear hereHow to validate JSON
JSON validation catches malformed data before it breaks your application. Instead of hunting through a stack trace from a failed API call, JSON Mint shows you the exact character where the parser choked. Paste your JSON and you will either see a green "Valid JSON" confirmation or a red error banner with line, column, and a human-readable description of the problem.
Validation runs entirely in your browser using JSON.parse, so your data is never uploaded anywhere. That makes JSON Mint safe for validating sensitive payloads like production API responses, secrets files, and internal configuration.
Frequently Asked Questions
How do I validate JSON?+
Paste your JSON into the editor. JSON Mint validates it in real time and shows a green checkmark if it is valid or a detailed error with line and column if it is not.
What counts as a JSON syntax error?+
Common issues include trailing commas, unquoted keys, single quotes instead of double quotes, missing commas, and unmatched braces or brackets. The error message tells you exactly what went wrong.
Does this follow the JSON spec?+
Yes — it uses the browser's built-in JSON.parse, which implements RFC 8259. That means it rejects comments, trailing commas, and single-quoted strings the same way production JSON parsers do.
Can I validate JSON against a schema?+
Not yet. This page checks syntax only. JSON Schema validation is planned for a future release.