Diceware Passphrase Generator

A strong password you can actually type and remember is an old problem, and the classic answer is the passphrase: words drawn at random, like 'pedra-farol-aveia-colar'. Here you pick 3 to 12 Portuguese words and a separator, and the phrase comes out with an entropy meter underneath showing, in bits, how expensive it is to brute-force. The draw uses the browser's cryptographic generator and nothing is sent to a server.

Passphrase strength is plain arithmetic: bits per word times word count, where bits per word is the log2 of the list size. Original Diceware uses 7,776 words at 12.9 bits each. The list on this page has about 100 Portuguese words, roughly 6.7 bits per word, and the on-screen meter reflects exactly that: 6 words land around 40 bits. The math assumes the attacker knows the method and the list; what protects you is the word count, not the secrecy of the recipe.

For a low-stakes account, 6 words will do. For a password manager master password or disk encryption, go up to 11 or 12 words and aim above 70 bits, or generate with a full-size Diceware list. Two practical rules: do not swap words by hand to make the phrase 'sound nicer', that cuts the randomness that gives it strength; and never reuse the same phrase across services. The draw runs entirely on your machine, using the browser's crypto API with bias-free sampling.