How to use BIP39 Seed Phrase Checker
Paste a BIP39 mnemonic only in a safe context. Review wordlist and checksum results. Never fund phrases you typed into a random site — prefer offline hardware flows.
Example: checking a test recovery phrase
The public BIP39 test phrase is the word “abandon” eleven times followed by “about”. It is a valid 12-word phrase used in documentation and must never hold real funds.
- Word count: 12 (valid counts are 12, 15, 18, 21 and 24)
- Every word is checked against the 2,048-word English BIP39 list
- The last word carries a checksum, so a single wrong word fails validation
The test phrase passes. Change one word, for example “about” to “above”, and the checksum check fails. Never type your real recovery phrase into any website.
Formula & methodology
Client-side @scure/bip39 wordlist + checksum validation for 12/15/18/21/24 English words. No network upload of the phrase.
Validate BIP39 checksums without leaving the browser
Checksum validity catches typos in recovery phrases, but a valid phrase can still be phished. Treat any hot-page entry as high risk.
CryptonicTools runs validation locally. For real funds, use vendor hardware wallets and offline procedures.
Pair with password strength and wallet address checks for hygiene — never share seeds in chat or screenshots.
All CryptonicTools utilities are free, mobile-first, and require no account.