Hybrid (Argon2id) is probably the safest bet if you are unsure. The specific modes are useful dependent on the threat model you are protecting against. Argon2i

Hybrid (Argon2id) is probably the safest bet if you are unsure. The specific modes are useful dependent on the threat model you are protecting against. Argon2i protects better against timing/side-channel attacks and Argon2d protects better against brute-forcing attacks. In my opinion, a developer should (in most cases) focus on application security instead of picking the perfect hashing algorithm, as application security is far more crucial.