Random Number Generator

Generating random numbers within a chosen range supports a surprisingly wide spread of tasks: drawing statistical samples for research, picking raffle winners, or simulating something like a lottery draw. It is not a tool for passwords or anything else that has to stay secret, for the reason explained below.

Under the hood, the tool uses your browser's built-in Math.random() function, a pseudorandom generator whose algorithm the JavaScript standard leaves to each browser. Each draw is scaled to a whole number between your minimum and maximum, both included, with every value equally likely. You set the minimum and maximum, how many numbers you want (1 to 100), and whether repeats are allowed; with repeats off, a value that was already drawn is simply drawn again. Turning Sort on lists the results in ascending order. Math.random() is not cryptographically secure, so for passwords or keys use a generator built on the Web Crypto API's crypto.getRandomValues().

Because the output is pseudorandom, it comes from a deterministic process, yet for nearly every practical purpose it behaves like genuine randomness. Where people go wrong is expecting a handful of draws to mirror the distribution of the full range. Five numbers from 1 to 100 will often bunch together or leave big gaps; that is ordinary sampling variation rather than bias, so interpret short sequences with appropriate caution.