Spin the Wheel

How to use Spin the Wheel

1. Enter your options, one per line — names, prizes, choices, anything.
2. Optionally set weights, and choose whether a winner is removed after each spin.
3. Spin. The winner is announced and added to the results log.

Is the result actually random?

Yes, and the distinction matters more than it might seem for something that looks like a toy.

Most spinning wheel sites use Math.random(), a fast pseudorandom generator whose internal state can be recovered from a handful of observed outputs. For a giveaway with real prizes, that is a genuine weakness — someone who can predict the sequence can predict the winner.

This wheel draws from crypto.getRandomValues(), the same cryptographically secure source used for key generation, and applies rejection sampling so that no segment is even marginally more likely than another due to modulo bias.

The visual spin is decoration applied after the fact. The winner is selected first, and the animation is calculated to land on it. That is how every implementation works, and stating it plainly is more honest than implying that physics is deciding.

How do weighted entries work?

Each entry can carry a weight that determines the size of its segment and its probability. An entry with weight 3 is three times as likely as one with weight 1, and its slice is three times as wide.

This is useful whenever the options are not equally likely by design: a raffle where people bought different numbers of tickets, a prize pool with a rare grand prize and common consolation prizes, or a decision where some options should be favored.

The wheel displays the computed probability next to each entry, so the odds are visible rather than implied by slice width. For a public giveaway, that transparency is worth having.

What is it used for?

• Classroom cold-calling. Picking a student at random is demonstrably fairer than a teacher choosing, and removes any perception of favoritism. Enable remove-after-spin to work through the whole class.
• Giveaways and raffles. A visible, animated draw is more convincing to an audience than a number appearing on screen. Screen-record the spin as evidence.
• Team decisions. Who presents first, who takes the on-call shift, which restaurant.
• Breaking a deadlock. When two options are genuinely equivalent, deciding by chance is faster than another meeting.
• Games and prompts. Truth or dare, writing prompts, workout selection, chore assignment.

How many entries can the wheel hold?

Practically, a few hundred. The constraint is legibility rather than computation — beyond about 40 entries the labels become too narrow to read on the wheel itself, and beyond about 100 the segments are a pixel or two wide.

Above that threshold the tool switches to displaying the entry count on the wheel and announcing the winner in the results panel instead of trying to label every slice. The selection is still uniform across all entries.

For a raffle with thousands of entries, a wheel is the wrong visualization. The random selection is still correct, but nobody watching can verify anything from a wheel with 4,000 invisible slices.

Frequently asked questions