json validator

Validate JSON syntax and get detailed error messages for malformed data.

JSON Validator checks whether your JSON input is syntactically valid according to the JSON specification. If the input is valid, it displays a success confirmation along with a prettified version of the parsed data. If the input contains errors, it provides the exact error message from the JSON parser, including position information to help you quickly locate and fix the problem.

This tool is essential for developers debugging malformed API responses, verifying hand-edited configuration files before deployment, validating JSON payloads before sending them to APIs, or quickly checking whether a string is valid JSON during troubleshooting. The detailed error messages save time by pinpointing exactly where the syntax breaks.

Paste your JSON into the text area, click the validate button, and instantly see whether your input passes validation. Valid JSON is displayed in a beautifully formatted preview that you can copy to your clipboard. Invalid JSON triggers a clear, specific error message describing exactly what went wrong and where.

All validation happens entirely in your browser using the native JSON parser — no data is transmitted to any server. Your JSON content remains completely private and secure. The tool is free, requires no account, and works on all modern browsers and devices.