JSON Validator

Strictly validate JSON and pinpoint any errors.

Input JSON

What is a JSON Validator?

A JSON Validator checks whether a JSON string is syntactically valid according to the JSON specification (RFC 8259). It pinpoints the exact line and character position of any errors, making debugging fast and easy.

Common Use Cases

Validating API request and response bodies
Checking JSON configuration files before deployment
Debugging JSON parsing errors in applications
Verifying JSON schema compliance

Tips & Best Practices

💡JSON keys must always be in double quotes
💡No trailing commas are allowed after the last item in arrays or objects
💡Use null (not None, nil, or undefined) for null values in JSON

Frequently Asked Questions

What makes JSON invalid?
Common causes: missing quotes around keys, using single quotes instead of double quotes, trailing commas, undefined or NaN values, or comments (JSON does not support comments).
What is the difference between JSON and JSONC?
JSONC (JSON with Comments) is a superset of JSON that allows // and /* */ comments. Standard JSON parsers do not accept comments — use this validator to check standard JSON compliance.