What is a seed phrase?
The 12 or 24 words that are, in effect, your whole wallet.
A seed phrase (also called a recovery phrase or secret recovery phrase) is a list of 12 or 24 ordinary words that a self-custody wallet creates. Those words can rebuild every private key in the wallet on any device, so whoever has them controls your crypto. Never share them with anyone, and never type them into a website, form or chat.
Never give your seed phrase to anyone and never type it into a website, form, email or chat. No exchange, wallet company, support agent, airdrop or "recovery service" ever needs it. Anyone who asks is trying to steal from you.
What it is
When you create a self-custody wallet, it generates a large random number and shows it to you as words from a fixed list of 2,048 words, usually English (a standard called BIP-39). The order matters. From those words the wallet can calculate all your private keys and addresses, for many different coins.
That's why the phrase is so powerful: if your phone breaks or your hardware wallet is lost, you can type the words into a new wallet and everything comes back. It's also why it's so dangerous to expose: a thief needs nothing else, not your phone, not your password, not your PIN.
What one looks like
A 12-word phrase looks something like this (a made-up example; never use a phrase you've seen anywhere else):
orbit · lemon · fragile · cattle · window · ozone · tackle · verb · humble · artist · sudden · mirror
Your wallet shows it once during setup, asks you to write it down, and usually checks a few words to confirm. Exchange accounts such as Coinbase or Kraken don't give you a seed phrase, because the exchange holds the keys (see custodial vs. non-custodial).
Example: restoring a wallet
Maria's phone is stolen. Her wallet app held $2,000 of crypto. On a new phone she installs the same wallet app (or any wallet that supports the same standard), chooses "import" or "restore," and types her 12 words in order. Her addresses and balances reappear, because they were never on the phone: they're on the blockchain, and the words regenerate the keys. If the thief had found her phrase written on a note in her phone case, they could have done the same thing first.
How to store it
- Write it on paper (or stamp it in metal for fire and water resistance) and check each word and its number carefully.
- Keep it offline. Not in photos, cloud notes, email, a screenshot or a document on your computer.
- Keep it private and safe: a safe, a lockbox or a secure place only you (and someone you trust) know about. Don't keep it in the same bag as your hardware wallet.
- Plan for your family. If something happened to you, would anyone know it exists? Leave instructions with your will, without the words themselves. See crypto estate planning.
How scammers steal seed phrases
The fake support agent
This is the most common trick, and it works like this:
- You post a question or complaint in public, for example on X, Reddit, Discord or Telegram: "My withdrawal is stuck."
- Within minutes, an account with your wallet's or exchange's logo replies or sends a direct message offering help. Some phone you, claiming to be from the exchange's security team, often using details from past data leaks.
- They send a link to a "support form," "wallet validation" or "sync" page, or ask you to read the words out "to verify ownership."
- As soon as you enter the phrase, a script empties your wallet, usually within seconds. The "agent" disappears.
Real support never DMs you first and never asks for your seed phrase, private key or remote access to your computer. If you need help, go to the company's website by typing the address yourself and open a ticket there.
Other common tricks
- Websites and ads that look like your wallet, asking you to "restore," "upgrade" or "claim an airdrop" with your phrase.
- Fake wallet apps in app stores and browser extension stores.
- Hardware wallets that arrive with a phrase already printed or filled in. A genuine device always makes you create a new one.
- Letters, emails or texts saying your wallet must be "re-verified" for a new law or security update.
- "Recovery services" that promise to get stolen crypto back for a fee, or that ask for your phrase to "trace" funds.
Not sure about a message? Run it through the scam checker. For long-term storage, metal plates, passphrases and inheritance, read wallet backups and tick through the recovery phrase checklist.
Common mistakes
- Taking a photo or screenshot "just for now." Photos sync to the cloud, and malware looks for them.
- Typing it into a notes app or password manager without understanding the risk if that account is breached.
- Using a phrase you didn't generate yourself, including from a "seed phrase generator" website or a pre-filled card.
- Writing it down wrong. A misspelled or missing word may make the backup useless. Some people test a restore with a tiny amount first.
- Cutting it in half and storing halves in two places. Each half gives a thief a big head start; use proper methods instead.
- Never checking it again. Paper fades and gets thrown out. Check your backup occasionally.
If someone may have seen your phrase
Act immediately: create a brand-new wallet with a new phrase on a device you trust, write the new phrase down properly, and move everything to it. Don't wait to see whether the thief strikes. The old phrase is permanently compromised. The emergency checklist lists every step.
The technical version
A 12-word phrase encodes 128 bits of randomness plus a 4-bit checksum (24 words: 256 bits plus 8). Each word represents 11 bits. The phrase is stretched into a 512-bit seed using PBKDF2, and keys are derived from it in a tree (BIP-32), so one phrase can create unlimited addresses across many coins. An optional extra word ("passphrase" or "25th word") creates an entirely different set of wallets. Guessing a properly generated 12-word phrase means searching about 2128 possibilities, which isn't feasible.
Check what you learned
3 quick questions. Answers stay on your device.
Frequently asked questions
What if I lose my seed phrase?
If you still have access to the wallet, move your funds to a new wallet with a new phrase you write down properly. If you've lost both the device and the phrase, the funds can't be recovered.
Will my wallet company ever ask for my seed phrase?
No. No legitimate wallet maker, exchange or support team will ever ask for it. Anyone who does is a scammer.
Can someone guess my seed phrase?
Not if your wallet generated it randomly. There are far too many combinations. Phrases get stolen, not guessed.
Should I use 12 or 24 words?
Either is secure if generated randomly and kept secret. 24 words adds extra margin; 12 is easier to write down correctly.
Can I change my seed phrase?
Not for an existing wallet. Create a new wallet, which gives you a new phrase, and send your funds to it.
Can I store my seed phrase in a password manager?
Some experienced users do, but it puts the phrase on internet-connected devices. Most security guides recommend offline paper or metal.
Is a recovery phrase the same as a password?
No. A password protects access to an app on one device. The recovery phrase is the wallet itself and works on any compatible wallet.
Do I have a seed phrase on Coinbase?
Not for a regular Coinbase account; the exchange holds the keys. Its separate self-custody wallet app (now called the Base app) does have one.
Where to next
Sources
- BIP-39: mnemonic code for generating keys
- BIP-39 English word list
- Ethereum security and scam prevention (ethereum.org)
- What to know about cryptocurrency and scams (FTC)
Written for beginners and checked against the sources listed. Last reviewed November 4, 2026. This page is educational and is not financial, tax or legal advice. How we write and check pages.