About this tool
What is BIP39?
The standard behind crypto wallet seed phrases: 12–24 English words from a fixed 2048-word list, encoding entropy plus checksum, convertible to HD wallet seeds. Lose the phrase, lose the wallet; anyone holding it owns everything.
How to use it
- Generate 12, 15, 18, 21 or 24-word phrases with valid checksums.
- Validate a phrase you already hold before trusting it.
- Learn the format — then go fully offline for real wallets.
Examples
- Understanding what your hardware wallet shows at setup.
- Verifying a paper backup transcribes to a valid phrase.
- Teaching how checksums catch one-word typos.
Important limitations
- A web page is the WRONG place for real funds: malware, extensions and screenshots steal phrases. Use hardware wallets offline.
- Anyone with your words controls your assets — no bank to call, no reversal.
- Passphrases (25th word) add protection but also a second thing you must never lose.
Privacy
Generated locally and never transmitted — but treat this page as educational only. For real value, generate and store seeds on air-gapped hardware.
Frequently asked questions
12 or 24 words?
24 for maximum entropy and long-term vaults; 12 is standard for everyday wallets.
Can I pick my own words?
Only from the official list and only via valid checksum math — human-chosen phrases are weak and often invalid.
What if someone sees my phrase?
Assume total compromise: move funds to a fresh wallet immediately.
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