The learning path
A seed phrase is twelve or twenty four words that encode the master secret your wallet derives every private key from. Enter it into any compatible wallet and all your accounts return. Anyone who obtains it can take everything, so it must be written on paper or steel, stored offline in at least two locations, and never typed into any website.
What the words actually are
Your wallet generates a large random number. That number is then encoded as words drawn from a standardized list of 2048, defined by a specification called BIP-39. Twelve words carry 128 bits of entropy. Twenty four carry 256.
Words are used instead of hex because humans copy words accurately and hex badly. Every word is unique in its first four letters, so even sloppy handwriting is usually recoverable.
One phrase, unlimited accounts
From that single seed, your wallet derives keys along a deterministic path. Account one, account two, account three, and separate branches for each blockchain. This is why one phrase restores everything, including accounts you created months later.
It is also why the phrase is so dangerous to expose. It is not a password to one account. It is the root of every account you will ever create in that wallet.
How to store it
Do this
Proven approaches
- Write by hand on paper, in clear block capitals, numbered one to twelve
- Make two copies and keep them in two separate physical locations
- For larger amounts, stamp it into a steel plate. Fireproof and waterproof
- Consider splitting across locations so no single one is complete, if you can manage the complexity
- Tell one trusted person where it is, without telling them what it is for
Never do this
Every one of these has cost people everything
- Photograph it. Phone photos sync to the cloud automatically
- Type it into notes, email, messages or a document
- Store it in a password manager, however good that manager is
- Type it into any website, ever, for any reason at all
- Keep the only copy in one place that a fire or flood could reach
The three ways people lose it
They never wrote it down
The wallet showed the words, they clicked continue, and months later the phone died. The funds are on the chain, visible, and unreachable forever.
They stored it digitally
A photo in the camera roll, a note in the cloud, a text file on the desktop. Malware scans for exactly this, and one compromised device empties everything.
They were talked into revealing it
A fake support agent, a fake wallet migration, a fake airdrop that needs to verify. All of them ask for the phrase. All of them are theft.
The optional twenty fifth word
Most hardware wallets support an extra passphrase, sometimes called a twenty fifth word. It is combined with your seed to produce a completely different set of accounts.
The benefit is real: someone who finds your written seed still cannot access the passphrase protected accounts. The risk is equally real: forget the passphrase and those funds are gone with no recovery, because it is not stored anywhere.
What happens if something happens to you
This is the part nobody plans for. If you are hit by a bus tomorrow, can your family access your holdings?
For most self custody users the honest answer is no, and the funds are lost permanently. Our recovery planning guide covers workable approaches, from sealed instructions with an attorney to multisig arrangements where a trusted party holds one of several keys.
Common questions
Is twelve words less safe than twenty four?
In practice, no. Twelve words provide 128 bits of security, which is beyond any conceivable brute force attack. Twenty four gives 256 bits. Both are far past the point where guessing is the threat.
Can I change my seed phrase?
Not directly. You create a new wallet with a new phrase and move the funds across. If you believe your phrase has been exposed, do this immediately, and move everything.
What if I am missing one word?
Recovery is sometimes possible because BIP-39 includes a checksum, so a tool can test candidates. Only use open source tools, run them fully offline on a machine with no network, and expect it to fail if more than one word is missing.
Is a bank safe deposit box a good place?
It is reasonable for one copy. Bear in mind access can be restricted during probate or by legal process, and that it is a single location. A second copy elsewhere is sensible.
Where to go next
Stuck on this one?
Some things click faster with someone walking you through them live. Orca sessions are one to one, screen shared, and paced for wherever you actually are.