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JSON Validator — Validate JSON Syntax Online

JSON Validator checks whether your input is valid JSON and reports the precise error location if not. It also shows the total character and byte count for valid JSON.

Common Use Cases

  • Verifying that a config file is valid JSON before use
  • Debugging malformed API responses
  • Checking JSON in CI/CD pipeline validation steps

Frequently Asked Questions

How does the JSON validator report errors?

If the JSON is invalid, the validator shows the error message from the JavaScript JSON.parse() engine, which includes the position information.

Privacy & Security

This tool runs entirely in your browser using client-side JavaScript. No data is sent to a server — your input never leaves your machine. SmartDevBox has no account system, no usage tracking, and no paid tier. See the Privacy & Security page for full details.

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