What is a random number generator?
A random number generator picks a number at random within the range you set. It is the most versatile tool for any number-based draw: you define a minimum and a maximum and get an unpredictable value within that interval, with the same probability for every number.
It works just as well for picking a number from 1 to 100 as for drawing among hundreds of numbered participants.
When to use the number generator?
- Numbered draws: assign a number to each participant and pick the winner.
- Guess-the-number games among friends or in class.
- Choosing at random a page, a row or a position in a list.
- Raffles and home lotteries with numbered tickets.
How does our generator work?
You set the range (minimum and maximum) and how many numbers you want (up to 50), and when you generate, the page uses the browser’s cryptographic generator (crypto.getRandomValues()) to produce each number within that interval. Every number in the range is equally likely. With “No repeats” (on by default) the numbers in one draw are all different; if you turn it off, each one is independent and can repeat.
The computation happens entirely in your browser, with nothing sent to a server.
What does “random” mean on a computer?
Computers don't improvise: they follow instructions. So when we talk about “random” numbers on a website, they're really pseudo-random: an algorithm starts from an initial value and produces a sequence so unpredictable and evenly spread that, for any everyday use, it behaves just like pure chance. This site uses the browser’s cryptographic generator (crypto.getRandomValues()), which also mixes in noise from your own device so the result cannot be predicted, and spreads results uniformly across the whole range. For a draw among friends, picking a number from 1 to 100 or deciding who starts, it's more than enough. The only thing it isn't suited for is draws with legal value, where certified and audited services are required.
Frequently asked questions
Can I choose the number range?
Yes. You set the minimum and maximum, and the result is always within that interval.
Do all numbers have the same probability?
Yes, within the chosen range every number is equally likely.
Is it valid for draws with legal value?
It uses the browser’s cryptographic generator, but the site is not audited or certified; use a certified service for official draws.
Can it repeat the same number?
Not within the same draw while “No repeats” is on (it is by default). Between draws, yes: each generation is independent, so a number can come up again.
How do I draw several numbers without repeats?
Choose how many numbers you want (up to 50) and leave “No repeats” on: every number in the draw will be different, perfect for raffle winners. If you need a list of names instead of numbers, try the name picker.
Can I generate negative or very large numbers?
Yes. The range accepts negative numbers and goes from −999,999 to 999,999. With “No repeats”, the range must contain at least as many numbers as you ask for.
What is a random number used for besides draws?
For lots of things: picking a question from a list, deciding turn order, assigning seats, drawing a random exercise in class, or even for homemade board games when you don't have dice handy.
How do I pick a random number from 1 to 100?
Set the range from 1 to 100 (or 1 to 10) and generate: you get a random number in that range, every number with the same chance. To pick several without repeats, choose how many you want and turn repeats off.
Related guides
- Random numbers: the guide — What “random” really means, how computers generate it, practical uses in draws and raffles, and the gambler's fallacy explained.
- How to do a fair random draw — Five steps that leave nobody room to complain: clean list, rules set in advance, a truly random method, recorded proof and backup winners.