Q: What is a BIP39 mnemonic phrase?
A BIP39 mnemonic phrase is a human-readable representation of a random number (entropy) used to generate cryptocurrency wallets. It consists of 12 to 24 words selected from a standardized list of 2048 words. This phrase allows you to back up and restore your wallet on any compatible software.
Q: Is it safe to generate mnemonics online?
This tool runs entirely in your browser using the Web Crypto API for secure random number generation. No data is sent to any server. However, for real-world wallet creation, it is recommended to use this on an air-gapped (offline) computer for maximum security.
Q: What is the difference between 12-word and 24-word mnemonics?
A 12-word mnemonic provides 128 bits of entropy, while a 24-word mnemonic provides 256 bits. Both are considered secure, but 24 words provide a higher level of security. Most modern wallets use 12 or 24 words.
Q: What is a passphrase in BIP39?
An optional passphrase (sometimes called the "25th word") adds an extra layer of security to your mnemonic. Different passphrases will generate entirely different wallets from the same mnemonic phrase. If you lose the passphrase, you cannot recover the wallet even with the correct mnemonic.
Q: What is the seed derived from a mnemonic?
The seed is a 512-bit (64-byte) value derived from the mnemonic phrase using the PBKDF2 key derivation function with 2048 iterations of HMAC-SHA512. This seed is used as the master secret for HD (Hierarchical Deterministic) wallet key generation as defined in BIP32.
Q: Can I use this tool for production wallets?
This tool is primarily designed for educational and development purposes. While it uses cryptographically secure random number generation, for production wallet creation you should use established wallet software on a secure, air-gapped device.