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Flip a Coin
Toss a virtual coin for a fair heads or tails decision. Every flip is a true 50/50, and the counters keep score of heads, tails and your longest streak.
Flip a Coin
How it works
Press Flip coin. The result is chosen by your browser’s secure random generator first, then the animation lands on that face. Press Flip 100 times to see how results even out over many tosses.
Is it really random?
Yes. Results come from crypto.getRandomValues(), the cryptographically secure generator your browser uses for encryption keys, with rejection sampling so every outcome is exactly equally likely (simple “modulo” tricks slightly favour some numbers). Nothing is decided in advance or sent to a server, so nobody — including us — can predict or influence a result.
Streaks are normal
Runs like five heads in a row feel suspicious but are expected: in 100 fair flips the longest streak is usually 6 or 7. The coin has no memory — after five heads, the next flip is still exactly 50/50. Believing otherwise is called the gambler’s fallacy.
Probability of getting the same side several times in a row
| Same side in a row | Probability | About 1 in |
|---|---|---|
| 2 | 25% | 4 |
| 3 | 12.5% | 8 |
| 4 | 6.25% | 16 |
| 5 | 3.125% | 32 |
| 6 | 1.563% | 64 |
| 8 | 0.391% | 256 |
| 10 | 0.098% | 1,024 |