Wallets · Bitcoin glossary

What is Seed phrase?

A human-readable backup used by many wallets to derive a deterministic set of keys.

Plain-English definition · Reviewed 2026-08-04
In one sentence

A human-readable backup used by many wallets to derive a deterministic set of keys.

01

Seed phrase meaning

A seed phrase, recovery phrase, or mnemonic is an ordered list of words encoding wallet entropy under a defined scheme. Compatible wallet software can use it to recreate a seed and derive keys. It is usually as sensitive as the wallet's private keys.

02

How it works in Bitcoin

Under BIP 39, wallet-generated entropy plus a checksum maps to words, and those words plus an optional passphrase derive a binary seed. Deterministic wallet standards then derive many child keys and addresses.

03

A simple example

A lost phone can be replaced while the wallet is recovered from its correctly recorded words and, if used, the exact passphrase. Recovery should be tested before relying on it.

04

Why Seed phrase matters

Wallet terms describe key control, signing and recovery rather than coins stored inside an application. The distinction becomes critical during backup or device failure.

05

What people often get wrong

Never invent your own phrase or enter one into an online form. Word order, spelling, wallet standard, derivation path, and optional passphrase all matter. Anyone with the backup may be able to spend the funds.

06

Quick checks before using the term

  • Who controls the spending keys?
  • How would recovery work after a lost device?
  • Has the backup been tested without exposing it?

Apply these questions to the concrete example above. A precise answer is more useful than repeating the definition without naming the actor, rule or failure path.

Check the primary reference

This entry is written in plain English, but the technical source is available when you need exact protocol detail.

BIP 39: Mnemonic Code ↗