Heads or tails, without hunting for a coin
Flipping a coin is probably the oldest and most widely accepted way of settling a dispute. Two options, the same chance for each, and a result nobody can argue with. The problem is that almost nobody carries coins any more.
This virtual coin does exactly the same thing from a phone. One tap, the coin spins and it lands on heads or tails. The mechanic is as old as it gets: two possibilities and fifty per cent for each.
It is the right tool whenever a decision between two options has to be made quickly and there is no way of reaching agreement: who starts, who chooses, who goes first or what gets done.
How to flip the coin
- Assign the options. Agree beforehand: what heads means and what tails means.
- Flip. One tap and the coin spins until it settles on a random result.
- Accept the outcome. That is the only rule of the game.
Worth knowing: each flip is independent of the last. Five heads in a row changes nothing about the probability of the next flip.
When a virtual coin comes in handy
Deciding between two options
When it is a tie and the decision has to come from someone who is not either of the two.
Sport and games
Drawing for the serve, the end of the pitch or who starts the match.
Classroom turns
Choosing which half of the class answers first or which team opens the activity.
Probability in maths
Flipping fifty times and comparing the real result with the theoretical fifty per cent.
Splitting chores
Who does the dishes, who takes the bins out or who drives home.
Icebreakers
Quick activities where chance decides who speaks or who answers.
Heads or tails: what probability says
A coin is the simplest example of randomness there is and, for that very reason, the best one for explaining how probability works:
Always fifty-fifty
Every flip has the same chance of landing heads or tails, regardless of what happened before. A coin has no memory.
The gambler's fallacy
If five heads come up in a row, plenty of people bet on tails convinced that it is "due". It is not: the probability of the next flip is still exactly one half. This mistake of intuition has a name of its own and is one of the most useful concepts you can teach with a coin.
Long streaks are normal
Across a hundred flips it is quite common for a run of five or six identical results to appear. It does not mean the coin is rigged; randomness produces streaks far more often than people expect.
The more flips, the closer to half
With ten flips, a 7 to 3 split is nothing unusual. With a thousand, the proportion gets very close to fifty per cent. That is the law of large numbers, and it can be demonstrated in class by flipping the coin many times.
Suggested activity: have each student flip the coin twenty times and record the results. Once the whole class's data is added up, the proportion will land far closer to 50% than any individual run did.
Features
- Immediate result. One tap and that is it, with no steps beforehand.
- A real fifty per cent. Each flip is independent and both faces have the same probability.
- No sign-up and no data. It stores nothing and asks you to create no account.
- Works on a phone. Built to be at hand whenever you need it.
- Free, no limits. Flip it as often as you like.
Flip the coin right now
One tap and it comes up heads or tails. Nothing to set up.
Flip the coin nowFrequently asked questions
How do I flip the coin online?
Is it genuinely random, or is it rigged?
Can several people use the same flip?
Do I need to install anything?
Is it useful for teaching probability?
Can I flip it as many times as I want?
More games and classroom tools
All of them are free, take minutes to set up and are shared with a single link.