Random.org is a website that produces random numbers based on atmospheric noise. In addition to generating random numbers in a specified range and subject to a specified probability distribution, which is the most commonly done activity on the site, it has free tools to simulate events such as flipping coins, shuffling cards, and rolling dice. It also offers paid services to generate longer sequences of random numbers and act as a third-party arbiter for raffles, sweepstakes, and promotions. Random.org is distinguished from pseudo-random number generators, which use mathematical formulae to produce random-appearing numbers.
