Generate strong, random passwords with your choice of length and character types, entirely in your browser — nothing you generate is ever sent anywhere. Use it when creating a new account, replacing a weak or reused password, or any time you need something a determined attacker can't easily guess.
How it works
Passwords are generated using your browser's Web Crypto API (crypto.getRandomValues), which draws from your operating system's cryptographically secure random number source — not the weaker Math.random() function many simple online generators use, which is predictable enough that it shouldn't be trusted for anything security-related. Each character is chosen independently and uniformly at random from the character sets you've selected, so a 16-character password using all four sets has roughly 94^16 possible combinations, making it effectively unguessable by brute force with current technology.
Worked example
A 16-character password using uppercase, lowercase, and numbers might look like aK3mZ9pQxL2vNt7R. Adding symbols to a 20-character password gives something like xT8!qR2@mK9#vL4$wZ7&, which is even harder to crack but occasionally awkward to type manually — a password manager handles that trade-off well.