How to use the Coin Flip
- Tap the coin, press Flip, or focus the coin and press Space or Enter.
- Watch the 3D toss and read the result. The tally, streak and history update after each flip.
- To toss several coins at once, set the number of coins (up to 100) or use a quick button such as Best of 3.
- Click Reset tally to start a fresh count. Your tally is kept on this device until you reset it.
Features
- Fair 50/50 results from cryptographically secure randomness
- Smooth 3D flip animation that respects reduced-motion settings
- Running heads and tails tally with percentages
- Current and longest streak tracking
- Flip up to 100 coins at once with a summary
- History of recent flips saved in your browser
Is a virtual coin flip fair?
A real coin is very close to fair, but not perfectly so. Researchers who studied coin tossing in detail found that a flipped coin lands on the side it started on slightly more often than half the time, because of the way it wobbles in the air. A virtual coin has no such physics. This tool reads one bit from crypto.getRandomValues, your browser’s cryptographically secure random generator, so heads and tails each have exactly a 50% chance on every flip, independent of every previous flip.
What to expect over many flips
Fair does not mean evenly alternating. Over 10 flips, getting 7 heads and 3 tails is common; the chance of an exact 5–5 split is only about 24.6%. As the number of flips grows, the percentage of heads settles closer to 50%, which is the law of large numbers, but the raw difference between heads and tails can still wander. Use the 100-coin button a few times and watch how the split changes.
| Flips | Chance of an exact 50/50 split | Chance of at least one run of 5 or more of the same side |
|---|---|---|
| 10 | 24.6% | about 22% |
| 20 | 17.6% | about 46% |
| 100 | 8.0% | about 97% |
Streaks and the gambler’s fallacy
After five heads in a row, many people feel tails is “due”. It is not. The coin has no memory, so the next flip is still exactly 50/50. Long streaks are a normal feature of random sequences: in 100 flips you will almost always see a run of five or more. The streak counters here are a fun way to see that in action, not a hint about what comes next.
Good uses for a coin toss
- Settling a choice between two options, such as who goes first or which of two restaurants to try.
- Sports and games that start with a toss to pick ends, serve or kickoff.
- Teaching probability: flip 100 coins and compare the result to the expected 50 heads.
- Best of three when a single flip feels too quick to be decisive.
A useful trick when you cannot decide: assign each option to a side and flip. If you feel disappointed by the result, you have learned which option you actually prefer. For more than two options, use Spin the Wheel; for numbers, try the Dice Roller or the Random Number Generator.
Frequently asked questions
Is this coin flip really 50/50?
Yes. Each result is one random bit from your browser’s cryptographically secure generator, so heads and tails are exactly equally likely and every flip is independent of the last.
Why did I get the same side many times in a row?
Streaks are normal in random sequences. In 100 fair flips a run of five or more identical results is very likely. The next flip is still a 50/50 chance.
Can I flip more than one coin at a time?
Yes. Set the number of coins to anything from 1 to 100, or use the quick buttons. You will see every coin and a summary of heads and tails.
Is my tally saved?
Your tally, streaks and recent history are saved in this browser’s local storage, so they survive a page reload. Reset tally clears them.