BIP39 Mnemonic Tool

Generate and validate BIP39 mnemonic seed phrases (12-24 words), view the underlying entropy, and derive the BIP32 master seed — with an optional passphrase. All client-side, nothing is sent anywhere.

No mnemonic generated yet

Choose a strength and click Generate.

Generates real BIP39 mnemonic phrases, entropy, and derived seeds — entirely client-side, nothing is sent anywhere. Anyone who sees a generated mnemonic can access anything derived from it; treat this the same as you would a real wallet seed phrase (i.e. don't use a phrase generated in a browser tab for real funds unless you fully trust the device it's running on).

BIP39 Mnemonic Tool

Generate and validate BIP39 mnemonic seed phrases (12-24 words), view the underlying entropy, and derive the BIP32 master seed — with an optional passphrase. All client-side, nothing is sent anywhere.

Common uses

  • Generate a 24-word mnemonic seed phrase
  • Validate an existing mnemonic's checksum
  • Derive the BIP32 seed from a mnemonic and passphrase

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Frequently asked questions

How do I generate a BIP39 mnemonic phrase?

Open the Generate tab of the BIP39 tool and choose 12, 15, 18, 21 or 24 words. It creates the mnemonic and shows the underlying entropy, all in your browser.

How can I check whether a seed phrase has a valid checksum?

Paste the words into the Validate / Seed tab. The tool checks the BIP39 checksum and tells you whether the mnemonic is valid.

How do I derive a BIP32 seed from a mnemonic and passphrase?

In the Validate / Seed tab enter the mnemonic and an optional passphrase. The tool derives the BIP32 master seed from them.

Should I use a seed phrase from an online generator for a real wallet?

For real funds, generate phrases on a trusted offline or hardware device. This tool is best for learning, testing and development, even though it runs locally in the browser.

Is my data uploaded to a server?

No. This tool runs entirely in your browser — your input is processed locally on your device and is never uploaded or stored on a server.