JWT Signature Verification — Verify Token Integrity
Quick Answer: Paste your JWT token and provide the signing key to verify the signature. For HS256, enter the shared secret. For RS256/ES256, paste the public key in PEM format. Verification confirms the token has not been tampered with since signing.
FAQ
What does JWT signature verification prove?
It proves the token payload has not been modified since the issuer signed it. A valid signature means the claims (user ID, roles, expiry) are trustworthy.
Is it safe to paste my JWT secret here?
The verification runs 100% in your browser. No data is sent to any server. For production secrets, prefer using your backend verification library.