Sign a token with your own key

Bring your own private key, generated with OpenSSL, and sign a JWT with it. Pick a signature family and the same payload is signed three times, once with each hash size, so the three can be compared. Verify any of them at jwt.io with the matching public key.

alg is rewritten when you sign, so each of the three tokens names the algorithm that actually produced it.
The same claims the other two generators use, so the tokens stay comparable.