How to make a strong password
The two things that make a password strong are length and randomness. A long password drawn from a large, unpredictable character set is exponentially harder to crack than a short or guessable one. Current security guidance favours length above forced complexity rules — a long random password (or passphrase) beats a short one peppered with symbols.
How password strength is measured
Strength is commonly expressed as entropy in bits — the base-2 logarithm of the number of possible passwords. For a random password it is:
With all four character sets enabled (about 94 printable characters), each character adds roughly 6.55 bits. A 16-character password is therefore around 105 bits — far beyond what's feasible to brute-force. As a rough guide, under 50 bits is weak, 50–80 is reasonable, and 80+ is strong.
Staying safe
This generator runs entirely in your browser using crypto.getRandomValues, a cryptographically secure source — nothing you generate is transmitted or stored. For real accounts, use a unique password everywhere and store them in a reputable password manager, and turn on two-factor authentication where you can.