Random Number Generator
Generate whole numbers in an inclusive range, with optional duplicate prevention.
Your result
MATHEnter your values and select generate.
On this page How it works & practical examples
How to use the Random Number Generator
Set the smallest and largest allowed integers and the number of draws. The browser’s cryptographic random source supplies random bits. Rejection sampling avoids the small bias that can arise when a random integer is simply reduced modulo a range size. If unique values are requested, previously drawn values are skipped. Generated results remain in the current page and are not stored.
The calculation
Worked example
A range from 1 to 6 can produce any face of a six-sided die. With duplicates disabled and six requested values, every value appears exactly once, in random order.
Assumptions and limits
A fresh result is produced when you press Generate; changing fields does not repeatedly draw numbers in the background. Up to 50 draws are supported, with endpoints between negative and positive one billion. A unique request cannot exceed the number of available integers. This interface is for everyday selections and simulations, not audited gambling, lotteries or password generation.
Common questions
Are the endpoints included?
Yes. Both the minimum and the maximum may be selected.
Why can a number repeat?
With duplicates allowed, every draw is independent. A repeated value is a normal outcome, not evidence that the generator is broken.