BIP-39 mnemonic validate
Check a BIP-39 mnemonic seed phrase against the English wordlist and its checksum, on your device.
BIP-39 mnemonic validate takes a pasted phrase, matches each word against the wordlist, and rechecks its checksum, then prints valid or invalid. An invalid result names the cause: an unknown word, a wrong word count, or a checksum mismatch. A valid phrase prints its entropy in bits and hex. It never checks whether that phrase controls a wallet holding funds.
Questions
What counts as invalid?
Three separate reasons, each named: a word that is not in the English wordlist, a word count that is not 12, 15, 18, 21 or 24, or a checksum that does not match.
What does a valid result show?
The word "valid", the word count, and the entropy in both bits and hex.
Does this check whether the phrase has funds?
No. It only checks the wordlist membership and the built-in checksum, nothing about any blockchain.
Can I use this from the command line?
Yes, this is a live text tool available on the page, the CLI and MCP.
Does it update as I type?
Yes, the tool is marked live, so it re-checks automatically as the pasted phrase changes.