Online tool for checking JSON syntax with error line and column hints.
JSON Validator is a free online tool for checking whether text is valid JSON. It is useful for API responses, webhook payloads, configs, and mock data before deploy. Processing runs locally in your browser and data is not sent to the server.
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JSON Validator checks JSON syntax and helps you quickly find errors in API responses, webhook payloads, configuration files, mock data, or objects before deployment.
The tool shows whether JSON is valid, outputs an error message, position, line, and column, and a fragment near the problem. For valid JSON it can show size, root type, object and array counts, key count, and maximum nesting depth.
Processing runs locally in your browser.