Seed

In the context of cryptocurrency, a seed — more formally known as a seed phrase or mnemonic phrase — is a series of words used to generate a private key, which in turn controls access to a cryptocurrency wallet. The seed is typically a set of 12 or 24 words drawn from a standardized wordlist, generated when a wallet is first created. This sequence of words encodes all the information needed to reconstruct the wallet and access its funds on any compatible device, making it the ultimate backup for your cryptocurrency holdings.

Seed phrases follow a standard called BIP-39 (Bitcoin Improvement Proposal 39), which ensures that wallets from different software providers are compatible with one another. This means that if your hardware wallet is lost or destroyed, you can recover your funds by entering your seed phrase into any other BIP-39 compatible wallet. Because the phrase deterministically generates the same set of keys every time, no information is ever permanently locked inside a single physical device.

Protecting your seed phrase is arguably the single most important aspect of cryptocurrency security. Anyone who gains access to your seed phrase has complete and irrevocable control of all funds associated with it. It should never be stored digitally — not in a photo, cloud document, email, or password manager — and should be written down on paper and kept in a secure physical location, ideally in multiple copies stored separately. Some users engrave their seed phrase on metal plates for protection against fire and water damage. No legitimate wallet software, exchange, or support representative will ever need to ask for your seed phrase.