What Is a Seed Phrase?
A seed phrase is a list of 12 or 24 ordinary words that generates every private key in your wallet. It is the master key to everything you own on-chain. Anyone who has it has your crypto. Anyone who loses it, permanently, has nothing. No company can reset it.
How It Actually Works
When you create a wallet, it rolls a huge random number and encodes it as words from a fixed list. From that one secret, the wallet derives all your addresses on every chain it supports. Restore the same words in any compatible wallet, anywhere on earth, and your funds reappear, because the funds were never in the app. They are on the blockchain. The phrase is just the key.
The Rules
- Write it on paper or steel. Never in a photo, a notes app, a password manager synced to the cloud, or an email draft.
- Never type it into any website, ever. No legitimate service asks for it. Everyone who asks is stealing from you.
- Store it offline, somewhere fire and flood will not take it.
- Test your backup by restoring it before you fund the wallet seriously.
- For meaningful amounts, pair it with a hardware wallet so the phrase never touches an internet-connected device.
When It Matters
The single most common way regular people lose crypto is mishandling this one piece of paper: phishing sites that ask for it, cloud backups that get breached, and phrases that were never written down at all. My Wallet Security and Self-Custody page covers the full checklist.