FairToss: Fair Coin Flip

Real coins aren't perfectly fair. FairToss is.

In a 2023 study, František Bartoš and colleagues at the University of Amsterdam recorded 350,757 real coin flips. The result, published in the Journal of the American Statistical Association (2025): a flipped coin lands on the same side it started on about 50.8% of the time. The starting side and the hand that tosses it leave a small but measurable bias.

FairToss removes both. Each result is picked by your phone's cryptographically secure random number generator - the same class of generator used to create encryption keys - before the animation even starts. There is no starting side and no hand, so every flip is an even 50/50 choice.

Don't take our word for it: open the Fairness screen and run 1,000,000 test flips right on your device. FairToss counts the results and runs a chi-square test so you can check the balance yourself.

THREE WAYS TO DECIDE
• Yes / No - for quick answers to everyday questions
• Heads / Tails - the classic coin toss
• Custom - put your own two options on the coin: "Pizza / Sushi", "Me / You", "Go / Stay"

A FLIP THAT FEELS REAL
• Smooth 3D coin toss with sound and haptic feedback
• Shake your phone to flip, or just tap
• History of your recent flips

RESPECTS YOU
• No ads
• No data collection - no accounts, no analytics, no tracking
• Works fully offline

Settle an argument with a friend, choose who goes first, pick dinner or break a tie. FairToss gives you a quick, honest answer - and the numbers to back it up.