Spinning wheel

Paste a list, spin, and get one name picked fairly. Names can be crossed off as they are drawn, and your lists stay in your browser for next time.

How it works

The wheel is the part you watch, but it is not the part that decides. When you press spin, the winner is chosen first — by a single draw against the list — and only then is the wheel animated so that it comes to rest on that name. That order matters more than it sounds. A wheel that worked the other way round, deriving the result from wherever a simulated spin happened to stop, would be impossible to test and impossible to make any honest claim about. Doing the draw first means the fairness of this tool is a property of a few lines of arithmetic that can be checked, rather than a property of an animation that cannot.

The draw itself uses your browser's built-in generator for security work, crypto.getRandomValues, with one refinement that most implementations skip. That generator hands back a number from a range of 2³² values. If you need a number from 0 to 9 and simply take the remainder, the first six values come up very slightly more often than the rest, because 2³² does not divide evenly by ten. The fix is to discard the small leftover block and draw again. That is what happens here, and it is why a pick is uniform rather than merely close to it.

We are careful not to overstate the case. You will sometimes read that Math.floor(Math.random() * n) is broken. It is not — its skew sits at around one part in nine quadrillion, which is not a defect in a tool that picks a name from a class register. The other generator is used because it costs nothing and lets the method be described precisely, not because the ordinary one would give you an unfair spin.

Chances, and what a weight actually means

Every name gets an equal share of the wheel unless you say otherwise. Under Adjust chances you can give a name a higher number, and the wheel visibly grows that name's slice to match. The numbers are whole numbers on purpose: a 3 means count this name three times, which is a thing you can picture and check against the picture. Fractional chances would invite a precision question the tool could not answer truthfully, and there is no ratio anybody can describe that whole numbers cannot express — twice as likely as one-and-a-half is simply 4 against 3.

Crossing names off

With cross each name off switched on, a name that has been picked moves to a tray below the wheel and is left out of the next spin. The wheel redraws with one fewer slice, so the remaining names each get a bigger share, exactly as they should. Any name in the tray can be put back individually, or everybody at once. This is the part that turns a single question into a session: picking eight presenters in order, working through a register, or drawing raffle entries one at a time without ever writing anything down.

Worked examples

A classroom register

Thirty-two names typed once, saved as “Year 9 set 2”, and still there the following Monday. Spin to pick who answers next, with crossing-off on so that nobody is asked twice before everybody has been asked once. The useful part is not the randomness — it is that the class can see it is random, and that you did not have to decide.

A raffle or giveaway

Paste the entrant names, turn crossing-off on, and draw first prize, second, third. Because each winner leaves the wheel, nobody can win twice, and the tray gives you the order you drew them in. A name that appears twice on your list genuinely has two chances, which is usually what people mean when they enter twice.

Deciding what to do

A wheel is not only for names. Chores, dinner, which of six half-finished jobs to pick up this evening, which board game. With equal weights it is a fair coin with more than two sides; with weights it is a way of leaning the chances toward the things you would rather do without removing the surprise altogether.

Sharing the same wheel with somebody else

Copy a share link produces a link that carries the list itself. Opening it anywhere loads the same names and the same chances. The list travels inside the part of the address after the #, which browsers never send to a server — so sharing a wheel does not upload your names to us or to anyone else. You can confirm that in your browser's network tab.

Questions people actually ask

Is the spin genuinely random, or does it favour the big slices visually?

It is genuinely random, and the slice sizes are the chances rather than a picture of them. A name with a weight of 3 occupies three times the arc and is three times as likely to be picked. Nothing about where the wheel starts, how long it spins, or where it stopped last time has any effect on the next result.

Are my names sent anywhere?

No. The draw happens inside your browser, and the lists you save are stored on your own device using your browser's local storage. Nothing is uploaded and no server here ever sees a name. You can check that yourself: open your developer tools, switch to the network tab, and spin. Nothing goes out.

What happens to duplicate names?

They are kept, and they each get their own slice. Two people in a group really can share a first name, and quietly merging them would remove somebody from the draw without telling you. If you paste “Ana” twice, Ana has two slices.

Will my list still be here tomorrow?

Yes, as long as you use the same browser on the same device and do not clear your site data. That is what the save button is for. A list saved here also opens in the other tools, so a roster typed once can be shuffled into a running order or split into teams without retyping it.

Can I turn the animation off?

It is already off if your device asks for reduced motion — the result appears immediately, with no spin, and it is exactly the same result. The wheel is decoration over a draw that has already happened, so removing the decoration removes nothing else. The pick is always announced as text below the wheel as well, so it never depends on watching anything move.

Limitations, stated plainly

• Saved lists are tied to one browser. They do not follow you to your phone, because there is no account and nothing is stored on a server. That is a deliberate trade: the privacy claim above is only true because there is nowhere else for the data to be.
• Clearing site data clears your lists. There is no copy elsewhere to restore from. A share link is the closest thing to a backup.
• Very long lists cannot be shared as a link. Rather than quietly dropping names to make one fit, the tool says the list is too long and tells you the limit — a link that silently omitted a few entrants would be worse than no link at all.
• Labels are hidden on a crowded wheel. Past a dozen entries the names would be too small to read, so the wheel shows the slices without them. The result is announced in text either way.
• Chances are whole numbers. There is no half-entry, by design.
• There is no sound. A wheel that started ticking in front of a class would be a defect rather than a feature, so it is not built yet.