If you're using JS to prehash before submission, an attacker who has exfiltrated hashes never needs to crack them. It also makes it impossible to degrade gracef

If you're using JS to prehash before submission, an attacker who has exfiltrated hashes never needs to crack them. It also makes it impossible to degrade gracefully for a non-JS client. You're effectively taking a password hash and turning it into an unhashed password itself.