Free online JWT validator. Check JWT structure, decode header and payload, verify expiration. Reports pass/fail for each check. Runs locally in your browser, no upload.
100% Local
How to Use the JWT Validator
Paste a JWT token into the input box. Click Validate JWT and the tool runs a series of structural checks on the token. Use Clear to reset both panels.
Checks performed
3-part structure — verifies header.payload.signature format
Header JSON validity — checks for alg claim
Payload JSON validity — decodes and validates the payload
Expiration — checks exp claim against current time
Metadata — shows iat, sub and iss claims
Features
Clear PASS/FAIL/WARN/INFO status for each check
Decoded header and payload are included in the report
Overall validity summary at the end
All processing runs locally in your browser. Your data is not uploaded to any server.