Seed

A Bitcoin seed (also called a seed phrase, mnemonic phrase, or seed words) is a simple way to back up and recover your cryptocurrency wallet. Instead of dealing with a huge, random number or a string of digits, the seed is shown as a series of easily remembered words. These words are picked from a standard list of 2048 possibilities defined by the Bitcoin protocol.

Each word in the seed stands for a part of the original random number, making it easy for humans to write down and store safely. This randomness, known as entropy, is crucial—if the original number isn’t truly random, someone could guess your seed and steal your funds.

Modern Bitcoin wallets use the seed as the starting point to generate all wallet addresses, public keys, and private keys. Thanks to deterministic design, entering the same seed always recreates the exact same wallet, which means you only need your seed to restore access to all your funds, no matter what device or software you use.

Seeds are the foundation for Hierarchical Deterministic wallets, allowing you to generate a practically unlimited number of keys and addresses from a single backup phrase. Internally, the seed is turned into a master private key which then creates the rest of your wallet keys and addresses. This structure helps you manage backups and increases your privacy by making address reuse unnecessary.

Seed phrases were standardized with BIP 39, while the way wallets handle these keys comes from BIP 32. Guard your seed phrase carefully—anyone with access to these words can control your bitcoins.