Mnemonic

A mnemonic phrase is a sequence of 12 to 24 simple words that serves as a backup for your cryptocurrency wallet. This phrase acts as a readable format of your wallet’s seed—a piece of data from which all keys in a hierarchical deterministic (HD) wallet are derived. You might also see it called a "seed phrase" or "recovery phrase."

The use of mnemonic phrases is defined by the BIP 39 standard, which is widely supported across Bitcoin wallets. For additional security, many wallets let you include a custom passphrase alongside your mnemonic.

Each word in a mnemonic comes from a fixed list of 2,048 possible words. Every possible combination forms a valid phrase and creates a unique set of cryptographic keys. With so many possible combinations—roughly 2.96 x 10^79 for a 24-word phrase—guessing someone’s mnemonic is practically impossible. Always keep your mnemonic phrase secure and never share it; access to the phrase is equivalent to access to your funds.