Coin Flip — flip a coin + odds calculator
Flip a coin online for an instant heads or tails with a running tally — then see the exact coin flip odds, streak probability and the provably-fair casino payout (a single flip pays 1.98×). Includes a fairness verifier and the truth about the gambler's fallacy.
| In a row | Probability | Odds | Ride payout* |
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Provably-fair demonstrator. The result is derived from the seeds before the flip — the same seeds always give the same side. Change the nonce for the next flip; you can't predict it.
Coin flip odds & streak probability
A fair coin is the simplest probability there is: each flip is exactly 50% heads, 50% tails, and every flip is independent of the last. The interesting part is streaks. The chance of getting the same side k times in a row is:
That's why long streaks feel rare — because they are. But a crucial catch: after four heads in a row, the fifth flip is still 50/50. The coin has no memory. Use the Streak odds tab to see the probability and casino payout for any streak length.
Provably-fair casino coin flip
On a provably-fair crypto casino, a coin flip is a pure 50/50 bet with a small house edge baked into the payout. You call heads or tails, and a correct call pays:
So instead of the "fair" 2× a true 50/50 would pay, you get 1.98× — that 0.01 gap is the 1% house edge, and it makes the expected return 0.5 × 1.98 = 0.99. Many casinos add a ride / streak mode: keep the same side and let winnings compound at 1.98× per flip. Five in a row pays about 30.4×, but because the edge compounds each flip, the expected return drops to 0.995 ≈ 95%. The longer you ride, the more edge stacks against you.
The gambler's fallacy
The single most expensive mistake in coin flip betting is the gambler's fallacy — believing that a run of heads makes tails "due". It doesn't. Each flip is independent: after ten heads in a row, the next flip is still exactly 50/50. Streaks of ten happen roughly once every 1,024 sequences, but once you're in one, the coin doesn't "know" it owes you a tail. Betting bigger to "correct" a streak is how bankrolls disappear. The flipper above is a great way to see it: flip a few hundred times and you'll hit surprisingly long runs, yet the overall split still homes in on 50/50.
Can you predict or hack a coin flip?
No. A fair coin — physical or provably-fair digital — is the definition of unpredictable. On a crypto casino each result is committed cryptographically from the server seed, your client seed and a nonce before you call it, so:
- A coin flip predictor can't know a result that is hashed and hidden — it's a 50/50 guess dressed up as a system.
- A coin flip hack that promises the next side is a scam; the outcome is committed and verifiable, not editable.
- There is no pattern and no "due" side — every flip is independent and random.
Is a casino coin flip rigged?
No — but it is not beatable either. A provably-fair coin flip lets you recompute the result from the revealed server seed, your client seed and the nonce, confirming it wasn't changed after your call. What you can't change is the built-in 1% house edge in the 1.98× payout — over the long run you get back about $0.99 per $1 wagered. Fair means honest and verifiable, not profitable. Only play with money you can afford to lose. 18+.