Random Number Generator
Enter your values below and click Calculate for instant results.
Generate random integers or decimals in any range. Options for unique numbers and multiple results.
Enter your values below and click Calculate for instant results.
A random number generator (RNG) produces numbers that have no predictable pattern, making them useful for games, statistics, research, security, and decision-making. This calculator generates cryptographically adequate random numbers using your browser's built-in random number capabilities.
True randomness is surprisingly hard to achieve with computers. Most software random number generators are technically "pseudo-random," meaning they use a deterministic algorithm seeded with an unpredictable value (like current time in milliseconds) to produce results that pass statistical tests for randomness. For everyday use, this is more than adequate.
Random number generators are used for selecting lottery winners and raffle prizes, assigning participants to treatment and control groups in research studies, generating statistical samples, making decisions when options are otherwise equal, creating game mechanics that require chance, and testing systems with random input data.
When the "no duplicates" option is selected, each number can only appear once in the results. This is equivalent to drawing numbered balls from a bag without replacement. When duplicates are allowed, each number is drawn independently, which is equivalent to rolling dice or spinning a wheel where the same result can appear multiple times.