JWT Decode / Verify
Decode JWT header and payload locally in the browser, verify HS256 / HS384 / HS512 signatures, and check common claims like exp, nbf, iss, aud, and sub.
JWT Decode / Verify Tool
The JWT decode / verify tool parses JSON Web Token header and payload locally in the browser, verifies common HS256, HS384, and HS512 signatures, and checks basic claims such as exp, nbf, iat, iss, aud, and sub, which makes it useful for auth debugging and token validation workflows.
How do you use it?
- Paste the full three-part JWT.
- Review the decoded header and payload.
- If you need signature verification, enter the secret and choose an algorithm or use auto detection.
- If you need claim validation, fill in expected issuer, audience, subject, or clock skew and run the check.
Features
- Decodes JWT header and payload locally
- Verifies HS256, HS384, and HS512 signatures
- Checks basic exp, nbf, iat, iss, aud, and sub claims
Why use this tool?
- Useful for checking whether frontend and backend JWT secrets, algorithms, and claims match
- Helpful for investigating expired tokens, not-before timing, and issuer / audience mismatches
- Saves you from writing one-off JWT decode and verification scripts