BIP-39 Mnemonic Validator

BIP-39 is the standard for generating mnemonic seed phrases — the 12 or 24 words that serve as a human-readable backup for cryptocurrency wallets. Each word comes from a fixed list of 2,048 English words, and the final word includes a checksum that verifies the integrity of the entire phrase. A valid mnemonic must have the correct word count (12, 15, 18, 21, or 24), use only words from the BIP-39 wordlist, and pass the checksum.

This validator checks all three conditions. It highlights any invalid words, verifies the word count, and computes the checksum to confirm the phrase is structurally valid. Everything runs locally in your browser — your seed phrase is never transmitted anywhere.

Security warning

Your mnemonic phrase is the master key to all funds in the associated wallet. Never enter a real seed phrase on any website you do not fully trust. This tool runs client-side with no network requests, but you should still exercise caution. For maximum security, use this tool on an air-gapped device or verify the source code yourself.