How this wheel picks a winner
When you press spin, the wheel asks your browser for a random number using crypto.getRandomValues. That is the same source browsers use for security work such as encryption keys. The number decides how far the wheel turns: between 5 and 8 full turns, plus a random stopping angle anywhere in the full circle.
The winner is whichever slice ends up under the pointer. The slowing down and the build up are just the animation catching up with a result that was set the moment you pressed the button. The spin length setting changes how long that takes, not who wins.
Why every name has the same chance
Every entry gets a slice of exactly the same size. The stopping angle is spread evenly around the whole circle, so each slice catches it equally often. With 8 names, each one wins 1 time in 8 over the long run.
Two things change the odds, and both are in your hands. Add a name twice and it gets two slices, so twice the chance. Remove a winner after a spin and the next spin only picks from who is left. Nothing else on the page weights the result. The wheel does not know who anyone is.
Truly random or just random enough?
Strictly speaking, no computer program is random the way radioactive decay is. Browsers use a cryptographically secure generator, seeded from unpredictable data collected by your device's operating system. Its output cannot be predicted, even by someone who has seen earlier results, which is a much higher bar than a picker needs.
Older and cheaper pickers often use Math.random, which is fine for games but is not built to be unpredictable. This site used to as well. It was switched to the secure version so that the promise of a fair pick is actually true. In a very old browser without secure random numbers, the wheel falls back to Math.random rather than failing.
Why the same name keeps coming up
Streaks are what real randomness looks like. With 10 names, the chance that the next spin repeats the last winner is 1 in 10. Spin just 5 times and there is about a 70% chance that some name comes up twice. People expect random results to be spread out evenly, so a repeat feels rigged when it is completely normal.
If repeats are a problem, press Remove Winner from List after each spin. That is the honest fix: it changes the rules from picking with replacement to picking without, and everyone can see it happen.
Questions
Can the person spinning control where it lands?
No. The stopping point is set by a random number the moment you press spin. How hard you click or when you click makes no difference.
Is the result decided before the wheel stops?
Yes. The stopping angle is chosen at the start and the animation plays out to it. That is how it can be both random and smooth.
Does it matter where the names are on the wheel?
No. Every slice is the same size and the stopping angle is spread evenly around the circle, so position makes no difference. Shuffle the list if you want it to look mixed.
Is wheelofnames.com random too?
We can only speak for this wheel, because we can see its code. The method described on this page is how spin-wheel.org works.
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