Bip39 online https://files.fm/u/2eemhhak2q#design Implementations like SLIP39 extend BIP39's abilities by splitting seed phrases into several shares, demanding a predefined threshold of shares to reconstruct the initial seed. This method improves protection by getting rid of solitary factors of failure. For words that only have three letters, there isn't a 4th https://dzen.ru/bip39-phrase.com