Got 11 phrases for recovery, how can I get the 12th?

[HeptaSean]

Yes, you have to check the possibilities for the missing words by hand.

The script above brings the possibilities down from 2048 (the whole list of words possible in BIP-39) to 128. It’s less than that for longer seed phrases (because we have more checksum bits, there).

I have given a script for different seed phrase lengthes in:

I lost my spending password and phrase seed

I have reimplemented @isferos’ idea in Python 3 for a flexible length seed length (12, 15, 18, 21, or 24 words): It is called with the words that you know as command line arguments and _ as placeholder for words you do not remember. If the last word of a 15 word Yoroi seed phrase is missing, it will give you exactly 64 possibilities (the last word encodes 11 bits, of which 5 bits are checksum, so 6 bits are part of the entropy and 2^6=64). For missing words in other places, the order of magni…

A more detailed usage explanation is in:

Am I screwed?

It does not need to be changed. The part you know is given on the command line with a _ replacing the word you do not know. (It expects exactly 12, 15, 18, 21, or 24 arguments on the command line, in your case 14 words and _ for the 15th that you do not know.) Attention: Never share the part you know here or somewhere else on the Internet. Even if you can’t crack it now, it might help others to crack it before you. It is Python 3, so you need that. If you are on Linux, it should already be the…

If you don’t know which of the words is missing, it will be much, much more possibilities (possible positions times possibilities per position 128 for 12 words, 64 for 15 words, …).

Someone could implement something that checks on blockfrost.io if there are transactions for the wallet that would be restored. Then, we would not need to manually restore to see lots of empty wallets.