Passphrase fork
There is no “wrong password” screen.
Select prepared inputs that remain distinct after BIP39 normalization and watch each one lead to a different fictional wallet rather than an authentication error.
No passphrase opens fictional wallet 9A3F · 21C8. The empty string is still an input to BIP39.
Every distinct normalized input takes a valid fork.
BIP39 first applies UTF-8 NFKD normalization, then derives a seed from the normalized mnemonic and passphrase. It cannot know which resulting wallet you intended.
Prepared input(empty)No passphrase
Demo wallet9A3F · 21C8fictional fingerprint
ValidationNonea typo still derives a wallet
The empty string is still an input to BIP39.
A passphrase can help after mnemonic exposure, but its exact spelling, storage, inheritance, and recovery become part of the security system.
There is intentionally no text field. Never type a real passphrase or recovery phrase into an educational website.