Random Password Generator

This userscript adds a Menu Entry in your userscript manager. Click that entry to generate a cryptographically secure random password. You can find it in your clipboard, ready to paste where you need to use it.

Rejection sampling approach

Rejection sampling is a technique that generates uniformly distributed random values by discarding any numbers that would introduce statistical bias when mapping a large random range into a smaller one. By accepting only values within a perfectly divisible interval and using a cryptographically secure RNG such as crypto.getRandomValues, it preserves true uniformity and unpredictability, which are essential properties for cryptographic-grade password generation.

Screenshot

Please note

• The default length of the password is 19 characters, you can adjust it by modifying the LEN constant in source code.
• This userscript was tested with Tampermonkey on Brave and Greasemonkey on Firefox.