Coin flip / coin-flip
Coin flip
Heads or tails, with streaks and history.
- Sourcecrypto.getRandomValues()
- Entropy—
- draws89
A coin is the simplest generator possible: one bit. Here the bit is read from crypto.getRandomValues() and mapped to heads or tails with an exact 50% probability. No ties, no coin rolling under the sofa.
The tool tracks streaks. Ten heads in a row feels impossible and yet happens once every 1,024 runs of ten: the feeling of a "hot coin" is a brain error, not a property of the coin.
How it works
- 01One click, one bit, one result. The spin is representation only: the value is decided before the animation.
- 02The current streak and the best streak of the session appear next to the result.
- 03History keeps the last twenty flips: enough to show that long streaks really happen.
Frequently asked
Coin flip
Is the coin really 50/50?
Yes: the bit is drawn uniformly. There is no compensation, so a run of heads does not raise the chance of tails next. That is the gambler fallacy, and it is arithmetically false.
Can I use it for something serious?
For reversible decisions yes. For official draws you need a verifiable process with minutes: this tool is transparent but not certified.
What does best streak mean?
The maximum number of identical consecutive results in the current session. Over fifty flips a streak of five or six is normal, not a signal.