Frequently Asked Questions

Almost. A fair coin gives heads and tails a 50% chance each. Real hand flips carry a tiny physical bias: in a 2023 study of 350,757 flips, Bartoš and colleagues found coins landed on the same side they started on 50.8% of the time. Across all flips, heads and tails still came out at 50.0% each. A digital coin flip has no physical bias at all.

Rest the coin on your curled index finger with your thumb underneath, then flick your thumb upward so the coin spins several times in the air. Call heads or tails while it is in the air. Catch it in your palm or let it land on a flat surface, and read the side facing up. Don't spin it on a table, because spinning is far more biased than flipping.

Neither. In the largest coin-flip experiment to date, with 350,757 hand flips, heads came up 50.0% of the time (95% interval 49.8% to 50.2%), so there was no heads-or-tails bias. The starting side was what mattered: coins landed the same way up they started 50.8% of the time. If nobody sees which side starts up, heads and tails are equally likely.

Yes. On FlipACoin you tap Flip and instantly get heads or tails, free and without an account. Each result is generated on our server and comes with a code you can check on the Verify page, so nobody, including us, can change it afterwards. You can also flip 100 times at once, play best of 3, or ask a yes-or-no question.

Heads is the obverse, the front of the coin, which usually shows a portrait, a head of state or a national emblem. Tails is the reverse, which usually shows the value or another design. The US Mint uses exactly these definitions. On coins without a portrait, the side with the country's name or coat of arms is normally treated as heads.

Because a real coin wobbles as it spins. In 2007, Persi Diaconis, Susan Holmes and Richard Montgomery showed that this wobble keeps the starting face up slightly longer, predicting about 51% same-side results for a caught coin. A 2023 experiment with 350,757 flips measured 50.8%. The effect depends on the starting side, not on heads versus tails, and it varies from person to person.

It is 1 in 8, or 12.5%. Each flip is independent with a 1/2 chance, so three heads in a row is 1/2 × 1/2 × 1/2. When you flip a coin 3 times, the chance of exactly 2 heads is 37.5% and of at least one heads is 87.5%. Five heads in a row is 1 in 32, and ten in a row is 1 in 1,024.

You will usually get close to 50 heads, but rarely exactly 50. The chance of exactly 50 heads in 100 flips is about 8%. The chance of 45 to 55 heads is about 73%, and of 40 to 60 heads about 96%. Streaks are normal too: there is a 54% chance of seeing seven or more of the same side in a row somewhere in 100 flips.

In a best of 3, you keep flipping until one side has won two flips, so a match takes two or three flips. Each player still has exactly a 50% chance of winning the series. Half of all best-of-3 series go to a deciding third flip, while in a best of 5 that drops to 37.5%. People use it because a single flip can feel too sudden for bigger choices.

A properly tossed coin gives both sides an equal chance, and neither person controls the outcome. The coin turns over many times in the air, so tiny differences in the flick decide the result. Statisticians Andrew Gelman and Deborah Nolan showed that even a weighted coin can't be meaningfully biased when it is flipped and caught. That is why referees use a coin toss to start football and cricket matches.

On FlipACoin, every result is fair and verifiable. A digital coin has no same-side wobble, so the real question is whether you can trust the site. Our server decides each flip and publishes a commitment, a cryptographic hash, before it happens. Afterwards it reveals the secret seed, so you can recompute the result in your browser on the Verify page and confirm nobody changed it.

Create a room in the FlipACoin app and share the 6 character code or link. Your friend opens it in the app; a link opened in a browser invites them to continue in the app. In the default Duel rule, the first player picks heads or tails and the other gets the opposite side, then you both watch the same flip live. Choose best of 1, 3 or 5, or join the worldwide Global Flip every five minutes.

Coin tossing goes back at least to ancient Rome, where it was called navia aut caput, "ship or head", after coins with a ship on one side and the emperor's head on the other. In medieval England it was called "cross and pile". Famous tosses include the 1845 best of three that named Portland, Oregon, and the Wright brothers' 1903 toss for the first flight attempt.

Yes, often in a surprising way. Assign each option to a side, flip, and notice your reaction. If you feel relief or disappointment, you have learned which option you really prefer. For yes-or-no questions, use a yes-or-no coin. To pick one person out of 2 to 8, Decision Mode in the app gives everyone an equal chance in a single go.

No. FlipACoin uses virtual coins only. They can't be bought, sent to other players or swapped for money, and you never risk coins on a result, so nothing of real value can be won or lost. Coins come only from playing, and they unlock every coin theme and effect. The only purchase is an optional one-time Remove Ads. Players under 13 can only use offline practice flips, with no account.

Heads or tails is the call you make before a coin flip. Heads is the obverse, the side that usually shows a portrait or emblem, and tails is the reverse. One person calls a side, the coin is flipped, and whoever matches the side facing up gets the choice. On a fair coin each call has a 50% chance, so heads or tails is a simple and fair way to settle a choice between two people.