d4 · tools · passphrase
Strong secrets with honest maths: memorable Diceware passphrases from the EFF large wordlist, or random character passwords, each with entropy computed from the actual wordlist and alphabet in use. Randomness comes from your browser's cryptographic generator. Everything runs in your browser; nothing you type leaves this page.
Words picked uniformly at random from the 7776-word EFF large wordlist. Each word adds log₂(7776) ≈ 12.925 bits.
Characters drawn uniformly from the alphabet you select. Entropy is length × log₂(alphabet size).
Diceware builds a passphrase by choosing whole words at random from a fixed list, the way rolling five dice selects one of 7776 entries. Because the words are independent and uniform, the strength is easy to state honestly: each word contributes exactly log₂(7776) bits. The entropy figures here assume the worst case, an attacker who already knows the method, the wordlist and every option you chose, and is left only to guess which words or characters came up. They do not count any reuse, dictionary or personal-information weakness, so treat them as an upper bound on secrecy, not a promise. A single appended digit or symbol adds only a few bits; length is what really matters.