[1] 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.

[2][3] The website was created in 1998 by Mads Haahr,[4][5] a doctor and computer science professor at Trinity College in Dublin, Ireland.

Random numbers are generated based on atmospheric noise captured by several radios tuned between stations.

[9] The generators produce a continuous string of random bits which are converted into the form requested (integer, Gaussian distribution, etc.)