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Password guides

Short, sourced answers to the questions people actually have about passwords.

NIST password rules (2025)What SP 800-63B-4 changed and what it means for you. How long should a password be?The numbers behind 12, 15 and 16 characters. Check if a password was leakedHow breach checks work without sending your password. Passphrase or password?Which to use, and where. How password generators workSecure randomness, bias and entropy.

Related tools and guides

Password generatorFree password generator that runs in your browser. Strong, random passwords and passphrases made with the Web Crypto API. Nothing is sent or stored.Passphrase generatorRandom words you can remember and type.Strength checkerTest a password and check it against known breaches.