Secure BIP-39 Generator
Generate a secure 12, 18, or 24-word recovery phrase for your Bitcoin wallet. Offline-first and cryptographically secure.
Why This Generator Is Secure
This tool generates a BIP-39 compliant Bitcoin seed phrase (12, 18, or 24 words) right in your browser, using top-tier cryptographic standards for maximum security.
Local Randomness: Powered by crypto.getRandomValues(), a cryptographically secure random number generator built into your browser. It pulls entropy (128, 192, or 256 bits) from your device’s OS—hardware noise, not weak guesses like Math.random(). No external servers involved.
Embedded Wordlist: Uses the official 2048-word BIP-39 English list, stored directly in this file. No network fetches mean no risk of tampering or interception.
Checksum Protection: Adds a checksum (4, 6, or 8 bits, based on word count) from a SHA-256 hash of the entropy. This makes your phrase valid and verifiable by standard wallets.
Offline Security: Save this as an HTML file (right-click, "Save As"), then open it locally with your browser disconnected from the internet. Running it offline eliminates browser risks like extensions or network leaks. For extra safety, use a clean browser with no extensions.
Wallet Compatibility: Your generated seed phrase works with most BIP-39 compliant wallets. Hardware wallets like Ledger (24 words default), Trezor (12 or 24 words), and KeepKey fully support it. Software wallets like Electrum, Blockstream Green, Coinomi, and Trust Wallet also recognize these phrases.
Safety Notes: The seed clears automatically after 5 minutes for your protection. For real funds, always consider a hardware wallet or a dedicated offline tool over a browser-based solution.