Random Number Generator

How the generator works

Choose the lowest and highest number, how many numbers you want and whether repeats are allowed, then press Generate. Each number is drawn with your browser’s cryptographic random number generator, the same source that decides every wheel spin on this site. Every number in the range has exactly the same chance.

The tool uses rejection sampling, which means it throws away values that would make some numbers slightly more likely than others. That avoids a subtle flaw called modulo bias that affects simpler generators. The range includes both end points, so a range of 1 to 10 can return 1 and 10.

Unique numbers and repeats

With repeats off, every number you get is different, like drawing numbered balls from a bag without putting them back. This is what you want for a giveaway or for picking several winners. If you ask for more unique numbers than the range holds, such as ten from 1 to 5, the tool tells you instead of failing quietly.

With repeats on, each draw is independent, like rolling a die several times. The same number can appear twice, and that is normal: in five draws from 1 to 10, there is about a 70 percent chance that at least one number repeats.

What people use it for

Teachers pick a student by roll number or a question by number. Game masters roll a d20 by setting the range to 1 to 20, or a percentile roll with 1 to 100. Organizers pick numbers for giveaways and event drawings. Families choose a number for a guessing game, and developers need a quick test value.

If you want people to watch the draw, use the wheel versions instead, such as the number wheel from 1 to 10, 1 to 20, 1 to 50 or 1 to 100, or the custom range wheel. For giveaways that others must trust, a verified draw lets anyone check the result.

Good to know

Nothing you generate is saved or sent anywhere. The numbers are produced in your browser, and a page refresh starts again. Random numbers do not follow patterns, so streaks and clusters are expected: seeing 7 three times in a row from 1 to 10 is unlikely on any given try, but it will happen to someone, sometime.