How the online coin flip works
Each flip uses your browser's cryptographically secure random number generator, so heads and tails each have exactly a 50% chance. The 3D animation is just for fun. The result is decided fairly the moment you flip.
Your stats stay on your device: total heads, total tails, the percentage split and your current streak. Flip a few hundred times and watch the split settle close to 50/50, which is the law of large numbers in action.
When to flip a coin
- Deciding who goes first in a game or kicks off in a match.
- Settling a friendly bet or a tie-break.
- Making a quick 50/50 decision when you are stuck.
- Teaching probability in maths class.
- Choosing between two options (heads = option A, tails = option B).
Is a real coin flip actually 50/50?
Surprisingly, not quite. Research by Persi Diaconis and later large-scale experiments found that a physical coin lands on the same side it started on slightly more often than half the time, roughly 51%. A virtual coin flip has no such bias: every toss is independent and exactly 50/50.
Odds of a streak
Each extra flip in a run halves the chance, so short streaks are common and long ones are rare.
| Same result in a row | Chance | Roughly |
|---|---|---|
| 2 | 25% | 1 in 4 |
| 3 | 12.5% | 1 in 8 |
| 5 | 3.13% | 1 in 32 |
| 10 | 0.098% | 1 in 1,024 |
A streak never makes the other side "due". Every flip is independent. Our guide Is a coin flip really 50/50? covers the research and the maths in full.
Coin flip games
- Best of three: first side to win two flips. Best of five and best of seven work the same way and take the sting out of a single unlucky toss.
- Heads or tails knockout: everyone stands and puts their hands on their head or their hips. Flip. Everyone who guessed wrong sits down. Repeat until one person is left.
- Streak challenge: each player calls heads or tails before every flip and keeps going until they are wrong. Longest run of correct calls wins.
- Probability experiment: predict how many heads you will get in 50 flips, then flip and compare with the counter.
More than two options?
A coin only settles a two-way choice. For three or more, use a tool built for it: the Dice Roller for up to six options, the Yes or No Wheel with a Maybe slice, or the Random Name Picker for any list.
Streaks, runs and the long run
Under the coin, the tool keeps score of more than heads and tails. It tracks your longest run of each side, shows the longest run you should expect for the number of flips you have made, and draws a chart of the share of heads after every flip. Early on the line swings wildly; as flips add up it settles towards the 50% line.
Press Flip 100 at once or Flip 1,000 at once to add a batch of instant flips and watch that happen in seconds. Once you have 20 flips it also tells you the range of heads that counts as ordinary chance, so you can see whether your results are unusual. Runs feel suspicious but are normal: the gambler's fallacy explains why a result is never due.
Frequently asked questions
What are the odds of five heads in a row?
One in 32, or about 3.13%. Each additional head in the streak halves the chance.
Does the coin remember previous flips?
No. Every flip is a fresh, independent 50/50 draw. A run of heads does not make tails any more likely on the next flip.
Is this coin flip random?
Yes. Each result comes from a cryptographically secure random generator with an exact 50% chance of heads or tails, and previous flips have no effect on the next.
Can I flip a coin best of 3?
Yes. Just keep flipping; the counter shows how many heads and tails you have, so you can play best of 3, 5 or any number.
What does the streak mean?
The streak is how many times in a row the latest result has come up, for example three heads in a row.
Can I flip with the keyboard?
Yes. Press the Space bar to flip.