What is a seed phrase?

When you create a self-custody wallet it shows you a sequence of words — typically 12 or 24, drawn from a standard list. Those words encode the master secret from which every key in the wallet is derived. Enter them into any compatible wallet and your funds reappear, because the keys are regenerated from the same seed.

This is why the seed phrase is the single most sensitive thing in crypto. It is not a password protecting an account; it is the account. There is no second factor behind it and no way to revoke it.

Practical rules. Write it on paper and store it somewhere physically secure — ideally two locations, so a fire or flood does not destroy the only copy. Never photograph it, never type it into a website, never store it in a cloud note, email or password manager. Never enter it anywhere except your own wallet app during a deliberate restore.

Every “wallet validation”, “support agent” or “airdrop claim” that asks for a seed phrase is a theft, without exception. There is no legitimate reason for anyone to see it.