Coin Flipper
Flip a virtual coin. Track heads vs tails over multiple flips.
Flip History
Press Space to flip again.
This tool is for informational and educational purposes only. It is not a substitute for professional financial, medical, legal, or engineering advice. See Terms of Service.
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Request a ToolHow to Use the Coin Flipper
Click the Flip Coin button or press Space to flip. Each result is shown with an animated coin graphic and added to your history. The heads and tails count updates automatically.
Use this tool to make random 50/50 decisions, settle debates, play games that require a coin flip, or run probability experiments to see how close to 50/50 random flips really are.
About Coin Flipping and Probability
A fair coin flip has a 50% probability of heads and 50% probability of tails. However, individual sequences of flips can deviate significantly from 50/50. Getting 7 heads in a row has a probability of about 1 in 128 and is not as rare as it feels. The Law of Large Numbers says that as the number of flips increases, the ratio of heads to tails converges to 50/50. After 100 flips you might be at 55% heads; after 10,000 flips you will be much closer to 50%.
Frequently Asked Questions
Is a coin flip really 50/50?
A true fair coin flip is theoretically 50/50. However, research by Diaconis, Holmes, and Montgomery showed that a physically flipped coin lands same-side-up about 51% of the time due to the physics of spinning. The bias depends on which side is facing up when you start flipping. For practical purposes like making decisions, this tiny bias is irrelevant. Virtual coin flippers use a pseudo-random number generator that is exactly 50/50 by design.
What is the probability of getting 5 heads in a row?
The probability of getting 5 heads in a row is (0.5)^5 = 1/32, or about 3.1%. Getting 10 in a row is (0.5)^10 = 1/1024, about 0.1%. It feels very unlikely but it will happen naturally if you flip long enough. In a series of 100 flips, you have about a 96% chance of seeing at least one run of 5 or more of the same side.
Can I use this to settle a bet fairly?
Yes. This tool's coin flip is exactly 50/50 (using Math.random() which produces a uniform distribution). Both outcomes are equally likely on every flip regardless of previous results. The previous flip has no influence on the next one, which is a property called independence. The "gambler's fallacy" is the incorrect belief that after several heads, tails becomes more likely. It does not. Each flip is always 50/50.
How do I flip multiple coins at once?
This tool flips one coin at a time. To simulate multiple coins, use the Random Number Generator and set the range to 0-1, or use the Dice Roller with a d2 (not available as a standard option, but a result of 1 on d4/2 or d6/3 = heads). Alternatively, flip the coin multiple times in sequence using the Space bar shortcut. For probability experiments with many coins, the Dice Roller with a d2 approximation works well.