Random Number Generator

Generate one or more random whole numbers within any range you choose, with an option to avoid repeats. Useful for picking a raffle winner, rolling a virtual die, drawing lottery-style numbers, or any time you need an unpredictable number.

How it works

Numbers are generated using your browser's cryptographically secure random source (crypto.getRandomValues) with rejection sampling, rather than a simple modulo operation on a random value — a naive modulo approach very slightly favors smaller numbers in the range, an effect known as modulo bias, which rejection sampling eliminates so every number in your range has exactly the same chance of appearing.

Worked example

Generating 3 unique numbers between 1 and 49 (as in a typical lottery draw) might produce something like 7, 23, 41 — each drawn independently and without replacement when "no repeated numbers" is checked.