Strong Passwords: Length and Randomness
Learn what a password generator can and cannot guarantee, why length and randomness matter, and how to store unique passwords safely.
Read more→Free secure password generator using Web Crypto API. Adjustable length, character types, entropy analysis, and bulk generation. No sign-up needed. Try now.
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Generate cryptographically secure passwords using the Web Crypto API. Customize length, character types, and analyze password strength.
Includes visual strength meter, entropy calculation, brute-force time estimation, and bulk generation of multiple passwords.
Local cryptographic generation, entropy analysis in bits, brute-force time estimation, support for uppercase, lowercase, numbers, and symbols.
A strong password combines three key factors: length, complexity, and uniqueness. Length is the most important factor: each additional character exponentially multiplies the number of possible combinations. A minimum of 16 characters is recommended for important accounts. Complexity means mixing uppercase letters, lowercase letters, numbers, and special symbols, which vastly expands the search space for an attacker. Uniqueness means never reusing passwords across different services; if one leaks in a data breach, your other accounts remain protected. Avoid dictionary words, proper names, birthdates, or predictable sequences like 123456 or qwerty. Our generator creates random passwords that automatically meet all of these criteria.
Entropy measures the unpredictability of a password in bits. The more bits of entropy, the harder it is to crack through brute force. An 8-character password using only lowercase letters has approximately 38 bits of entropy, which a modern computer can break in minutes. Adding uppercase, numbers, and symbols raises the entropy to about 52 bits. Increasing the length to 16 characters with all character types can exceed 100 bits of entropy, which would take billions of years to crack with current technology. Security experts recommend at least 60 bits for general accounts and over 80 bits for critical accounts like online banking or your primary email. Our generator displays the exact entropy of each generated password and estimates the time required to crack it.
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Learn what a password generator can and cannot guarantee, why length and randomness matter, and how to store unique passwords safely.
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Read more→Passwords are generated locally in your browser using the Web Crypto API. No passwords are sent to or stored on any server.