Coin Flip
What Is a Coin Flip?
A coin flip is the simplest form of random binary decision — producing one of two equally likely outcomes (heads or tails). In probability theory, a fair coin flip represents a Bernoulli trial with a 50% chance for each outcome. This tool simulates coin flips digitally using a cryptographically secure random number generator, ensuring the same fairness as a well-balanced physical coin. You can flip multiple coins simultaneously to observe probability distributions in action.
How to Use
Click the Flip button to flip a coin. Choose the number of coins to flip at once (1-100). Results are displayed with a running tally of heads and tails. Use the Clear button to reset the history.
Fairness
Each flip uses a cryptographically secure random number generator (crypto.getRandomValues) to ensure a fair 50/50 probability. The results are truly random and not predetermined.
Common Use Cases
- Quick decision making — settle simple either/or choices fairly
- Probability learning — observe how results approach 50/50 over many flips
- Games — determine who goes first or make random selections
- Teaching — demonstrate the law of large numbers and probability concepts
- Sports — simulate a coin toss for team selection or field choice
Features
- Flip 1 to 100 coins at once
- Running tally tracking heads and tails counts
- Flip history with clear option
- Cryptographically secure 50/50 fairness
- Instant results with visual feedback
Privacy
All processing happens in your browser. No data is sent to any server.
FAQ
Are heads and tails really a 50/50 chance?
Yes. Each flip uses the browser's cryptographically secure random number generator (crypto.getRandomValues), with heads and tails equally likely. The outcome is not predetermined and is as fair as a well-balanced physical coin.
I got heads several times in a row — is it broken?
No. Each flip is an independent trial, so short streaks are normal and expected. The more you flip, the closer the ratio of heads to tails gets to 50/50, by the law of large numbers.
Is there a limit on how many coins I can flip at once?
You can flip up to 100 coins at a time. When you flip multiple coins, the running tally of heads and tails updates automatically.
Are my results or history sent or stored on a server?
No. The random generation and the tally both happen entirely in your browser. Your flip results and history are never sent to a server or stored anywhere.
How does the history work, and can I reset it?
Each flip is added to the history and the running tally. Press the Clear button to reset the history and counts so you can start a fresh session from zero.