Random Number Generator

A random number generator (RNG) produces unpredictable numbers within a range you choose. The quality of an RNG matters: most browser-based generators quietly rely on Math.random(), which is fast but is a pseudo-random algorithm not designed to be cryptographically secure and is not guaranteed to be uniformly distributed. This tool instead uses the Web Crypto API's crypto.getRandomValues(), which draws entropy from the operating system's secure random source, the same source used to generate encryption keys and authentication tokens. You set a minimum and maximum, choose how many numbers to draw, and decide whether duplicates are allowed. With duplicates off, the tool produces a unique set (sampling without replacement), which is what you want for picking distinct lottery numbers or drawing winners from a list. A key constraint follows from that: when duplicates are disabled, the count you request cannot exceed the size of the range, because there are only so many distinct values to choose from. To avoid modulo bias, where naively mapping raw random bytes onto a range subtly favors some values, a correct implementation rejects and re-rolls out-of-range samples rather than taking a plain remainder. Cryptographic randomness is deliberately non-reproducible, so there is no seed to recover a previous sequence. Everything runs in your browser with no network requests, no logging, and no account, which keeps draws fair and private whether you are rolling dice for a board game or generating test data. Because the generation is instant and unlimited, you can re-roll as many times as you like, and nothing about your draws is ever recorded or sent anywhere.