Flip a Coin Online
Heads or tails? Flip a fair virtual coin with one click, keep a running tally, or flip a thousand at once to watch the odds even out.
How to flip a coin online
- Click "Flip the coin". The coin spins and lands on heads or tails.
- The tally keeps count of heads, tails and your current streak.
- To run an experiment, enter a number and flip up to 1,000 coins at once to see how close to 50/50 they come.
Is a virtual coin flip fair?
Each flip is decided by your browser's cryptographically secure random number generator, so heads and tails are exactly 50/50 and every flip is independent of the last. A real coin is actually very slightly biased: research by statistician Persi Diaconis found that a tossed coin lands on the same side it started on about 51% of the time. A virtual coin has no such wobble.
Streaks feel suspicious but are completely normal. In 100 flips of a fair coin, a run of six or seven of the same side in a row is more likely than not. That is the gambler's fallacy at work: after five heads, the next flip is still exactly 50/50. Try the "flip many" feature with 1,000 coins and you will usually land within a few percent of half and half, which is the law of large numbers in action.
Use it to settle a tie, decide who goes first, make a quick yes/no call, or demonstrate probability in class. For more than two options, try the dice roller or spinner wheel.
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Frequently asked questions
Is this coin flip random?
Yes. It uses crypto.getRandomValues, the browser's secure random source, so every flip is a true 50/50.
What are the odds of getting heads 5 times in a row?
1 in 32 (about 3.1%), since each flip is 1/2 and 1/2 × 1/2 × 1/2 × 1/2 × 1/2 = 1/32.
Why do I keep getting long streaks?
Streaks are normal in random sequences. In 100 flips you should expect at least one run of 5 or more.
Can I flip more than one coin?
Yes. Use "Flip many coins at once" for up to 1,000 flips with a heads/tails count and percentage.