Random Number Generator

How this random number generator works

Pick a range, choose how many numbers you need, and press Generate. Every whole number from From to To has the same chance of being chosen.

Wheelova uses your browser's crypto.getRandomValues(). According to MDN, browsers implement it as a cryptographically secure pseudo-random generator seeded with system entropy — the same kind of source used for security features. It is unpredictable in practice, but it is not a physical "true random" device such as atmospheric-noise generators.

To turn a random value into a number in your range, the tool scales it to the size of the range and rounds down. With ranges below a few million, any bias from this step is far too small to matter for games, classrooms or draws.

Pseudo-random vs. true random — what's the difference?

There are two broad kinds of random number generator:

Ordinary PRNGs (like many programming languages' default random() functions) can be predicted if someone knows the seed. A cryptographically secure PRNG, like the one browsers expose through crypto.getRandomValues(), is designed so that past output does not let anyone predict the next number. For picking a winner, a seat number or a game move, that is more than enough.

Repeats or no repeats?

• No repeats works like drawing numbered tickets from a hat: once a number is drawn, it can't come up again in the same batch. Use it for raffles, seat assignments, test-question order, or choosing several winners. You can't ask for more unique numbers than the range contains — 1–10 has only ten.
• Repeats allowed works like rolling a die again and again: every draw is independent, so the same number can appear twice. Use it for dice games, simulations and practice problems.

What are the odds? A quick reference

With one number drawn from a range, every number has a chance of 1 ÷ (size of the range):

Repeats are more common than people expect. If you draw numbers from 1–100 with repeats allowed, the chance that at least two match is about 10% after 5 draws, about 37% after 10 and about 87% after 20 — the same maths as the "birthday problem". If repeats would spoil your draw, tick No repeats.

Worked examples

Raffle with 250 tickets, 3 prizes. Set 1 to 250, How many = 3, tick No repeats, and press Generate once. Read the winners in order — first number for first prize, and so on — and announce that order before you press the button.

Pick a random student by roll number. Class of 32: set 1 to 32, How many = 1. For a fresh number each time without repeats across the lesson, use the Name Picker Wheel with "remove winner" instead.

Four-digit PIN for a game or puzzle. Set 1000 to 9999, How many = 1. (Don't use generated numbers for real bank or account PINs — let your bank's own system create those.)

Shuffle question order for a quiz with 15 questions. Set 1 to 15, How many = 15, No repeats on, Sort off. The result is a random order of all 15 questions.

Ideas for using random numbers

• Classrooms — question numbers, page numbers, seating, maths warm-ups ("multiply the two numbers you get").
• Games — replace a lost die (1–6) or a 20-sided die (1–20), pick a level, set a score target.
• Giveaways — draw ticket numbers live on screen. For named entrants, the Raffle Wheel shows the draw visually.
• Everyday picks — which restaurant on a numbered list, which chore, which movie from a ranked watchlist.

When not to use it

This generator is right for games, teaching, raffles and everyday decisions. It is not a certified gaming or lottery system, and it should not replace audited draw software where the law requires it. It also isn't meant for generating passwords or encryption keys — use a password manager or your platform's key-generation tools for that.