Coin flip

Heads or tails in one tap. Settle who goes first, flip best of three, or toss a hundred coins for a probability lesson.

Session: 0 heads · 0 tails

Roll history

Your results appear here and stay on this device only.

Is a streak of heads suspicious?

Most people, asked to write down a "random" list of flips, never put more than three the same in a row. Real coins do it constantly. Set a number of flips and a streak length:

45.8%

chance that 20 fair flips contain a run of 5 or more identical results (heads or tails). In 20 flips the typical longest run is about 4.

And the next flip after five heads? Still exactly 50/50. The coin has no memory; believing a tails is "due" is the gambler's fallacy.

Calculated exactly with a run-length recurrence, not simulated.

Ways to use a coin flip

  • Who goes first: call it before the flip, then tap once.
  • A stubborn decision: assign each option a side. If you feel disappointed by the result, that tells you what you actually wanted.
  • A classroom experiment: set 100 coins and flip a few times. The heads share wobbles around 50% and rarely lands exactly on it, which is the law of large numbers in action.

Need more than two outcomes? Use the yes or no generator with a "maybe", a d6, or the random number generator.

Questions people ask

Is this coin flip 50/50?

Yes. Each flip draws one unbiased random bit from your browser's cryptographic generator, so heads and tails have exactly equal chances. The spin animation is decided before it starts and always lands on the drawn side.

Is a real coin toss fair?

Almost. A 2023 study by František Bartoš and colleagues, covering 350,757 hand-tossed flips, found coins land on the same side they started about 50.8% of the time. An online flip removes that tiny bias.

Can I flip more than one coin?

Yes: choose 1 to 100 coins. You get the heads/tails count, the sequence and the longest streak.

What does "best of 3" do?

It flips until one side has won two flips, the usual way to settle a disagreement that one flip does not.

Are my flips saved?

Results are kept in this browser's local history only, and you can clear them any time.