BIP39 passphrase generator — Guide
Generate a BIP39 passphrase from an existing or random mnemonic, or get the mnemonic from the passphrase.
What it is and when to use it
Work with BIP39: generate a fresh mnemonic phrase, or derive the passphrase/seed from an existing mnemonic and vice versa. BIP39 is the standard that turns a 12/24-word phrase into the seed behind crypto wallets — this tool implements it locally, so nothing you paste is transmitted.
Generates or validates BIP39 mnemonic phrases, and derives the seed from a mnemonic. Useful for wallets and key management.
How to use it
- Choose the mnemonic length (12 words is common)
- Click generate to get the phrase
- With an existing phrase, paste it in to validate and derive the seed
A worked example
Things that trip people up
- A mnemonic is equivalent to a private key: store it offline and never leave it in an online tool
Questions people ask
- What is a BIP39 mnemonic?
- A list of 12–24 words picked from a fixed 2048-word list. The words encode entropy plus a checksum, and the wallet derives all your keys from them — the phrase is the wallet.
- Is it safe to enter my real mnemonic here?
- The tool runs entirely client-side and sends nothing anywhere. Still, the security advice is absolute: a mnemonic that protects real funds should only ever be typed into a trusted, offline device.
- Why does one mnemonic produce many keys?
- The mnemonic seeds a hierarchy (BIP32): one seed deterministically derives an entire tree of account keys. Losing the phrase therefore loses every derived account, and anyone holding it holds them all.
Next steps
Open the BIP39 passphrase generator tool
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