A set of 12 or 24 words that serves as a human-readable backup of your private keys. With your seed phrase, you can recover your entire Bitcoin wallet on any compatible device. It must be stored securely offline.
A set of 12 or 24 words that serves as a human-readable backup of your private keys. With your seed phrase, you can recover your entire Bitcoin wallet on any compatible device. It must be stored securely offline.
A seed phrase (also called a recovery phrase or mnemonic phrase) is a sequence of 12 or 24 words from a standardized list of 2,048 English words (defined by BIP-39). This word sequence encodes the master private key from which all keys in a wallet are derived. With just these words, you can recover your entire wallet — all addresses, all balances, all transaction history — on any compatible hardware or software wallet.
The seed phrase system was designed to solve the problem of backing up complex cryptographic keys. Instead of dealing with raw 256-bit numbers or hexadecimal strings, users write down a sequence of common English words. The words include a checksum, so entering a wrong word will be detected. The phrase deterministically generates the entire key hierarchy (following BIP-32/44), meaning the same words will always produce the same set of addresses.
Seed phrases are both the most powerful and most vulnerable part of Bitcoin security. Anyone who obtains your seed phrase has complete access to your Bitcoin — there is no additional password or two-factor authentication protecting it (unless you use an optional passphrase, sometimes called the 25th word). This is why seed phrases must be stored offline on durable material (steel plates are recommended), in physically secure locations, and never entered into any internet-connected device, website, or cloud service.
If someone obtains your seed phrase, they can immediately generate all your private keys and steal all Bitcoin associated with that wallet. There is no time delay, no secondary verification, and no recourse after the theft. This is why physical security of your seed phrase backup is critical. If you suspect your seed phrase has been compromised, immediately transfer all funds to a new wallet with a fresh seed phrase.
You cannot change the seed phrase associated with an existing wallet — the mathematical relationship between the phrase and the keys is fixed. If you want a new seed phrase, you must create a new wallet and transfer your Bitcoin to it. This is recommended if you believe your current seed phrase may have been compromised or if you want to upgrade from a 12-word to a 24-word phrase for additional security.
A passphrase is an optional additional word or phrase that can be added on top of the standard 12/24-word seed phrase. It creates an entirely different set of keys and addresses — effectively a hidden wallet. If someone finds your seed phrase but does not know the passphrase, they will only see the base wallet (which could be empty or contain a small decoy balance). The passphrase adds significant security but also adds risk — if you forget the passphrase, the associated funds are lost forever.