Coin flip: toss a coin in one tap
Flipping a coin is the oldest and cleanest way to hand a decision over to chance. With this tool you press Flip, the coin spins in 3D right inside your browser and lands showing heads or tails. You do not need a real coin in your pocket or an argument about who gets to toss it: the outcome is impartial and nobody can be accused of cheating.
Beyond a single coin, you can flip several at once (up to 100) and see at a glance how many landed heads and how many landed tails. The tool also keeps session statistics: every toss adds to the running totals for heads and tails, with percentages, so you can watch with your own eyes how the split creeps toward 50/50 as you repeat.
What flipping a coin is good for
- Deciding between two options: who does the dishes, whether to go out or stay in, which place to pick. One side per option and you are done.
- Board games and playground games: choosing who goes first, breaking a tie, sharing out turns without arguing.
- Quick draws: when there are only two people or two prizes at stake.
- The kickoff in sports: in soccer, tennis, volleyball or cricket the referee tosses a coin to decide the side or who serves first.
- Breaking a deadlock: sometimes, while the coin is still in the air, you already know which result you were hoping for. That trick works just as well with a virtual coin.
The 50/50 probability
A fair coin has two sides and no reason to favor one over the other, so each side carries a 50 % chance. This tool does not use Math.random, which is built for simulations, but crypto.getRandomValues, the browser’s cryptographically secure generator, with rejection sampling so that heads and tails are exactly equally likely. Neither side is favored and the outcome cannot be predicted.
Worked example
Because each flip is independent, the odds of a streak multiply. The probability of getting heads n times in a row is (1/2) raised to n:
| Heads in a row | Calculation | Probability | Roughly |
|---|---|---|---|
| 1 | 1/2 | 0.5 | 1 in 2 |
| 2 | 1/2 × 1/2 | 0.25 | 1 in 4 |
| 3 | (1/2)³ | 0.125 | 1 in 8 |
| 5 | (1/2)⁵ | 0.03125 | 1 in 32 |
Getting 5 heads in a row happens 1 time in 32. It sounds strange, yet if a group of 32 people each flip 5 coins, you would expect one of them to hit all five heads. It is not magic; it is chance.
Why random sequences look non-random
True randomness produces streaks. Our intuition expects something neatly alternating like heads-tails-heads-tails, but a genuine sequence often has runs such as heads-heads-heads-tails-tails. When several heads show up in a row, many people feel that tails is “due”. That is the gambler’s fallacy: the coin has no memory. After four heads, the fifth flip is still 50/50, exactly like the first. Past results never change future ones.
Frequently asked questions
Is the result really 50/50 and fair?
Yes. Each toss is decided with crypto.getRandomValues, the same source of randomness used for security keys, and any bias is removed with rejection sampling. Heads and tails are equally likely, and nothing is rigged.
Can I flip several coins at once?
Yes. Type how many you want (from 1 to 100) and press Flip. You will see them all spin and, once they land, a count of how many came up heads and tails on that flip, plus the running session total.
Why did I get 5 heads in a row? Is it broken?
No, that is perfectly normal. Each flip is independent, so streaks happen: 5 heads in a row occurs 1 time in 32. The coin neither “remembers” earlier tosses nor “owes” you a correction. Flip many more times and the totals will drift toward 50 %, as the session statistics show.