Customisable Coin Flip

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Flip a Coin - Only Heads

A customisable coin: set both sides to your own labels and click to flip

Click the coin below to flip it ↓

Heads

How to Use

  1. 1
    Both fields are pre-set to Heads. Change them to any labels you like - e.g. "Option A" and "Option B".
  2. 2
    Click the coin in the centre of the screen to trigger the flip animation.
  3. 3
    After the spin, the result from one of your two labels is revealed.
  4. 4
    Keep both labels as "Heads" to simulate the thought experiment - or use it as a custom decision tool.

What Is "Flip a Coin Only Heads"?

This page explores a fascinating probability thought experiment: what if every coin flip landed on heads? With a fair coin, the chance of heads on any single flip is exactly 50%. Getting heads twice in a row is 25%. Ten times in a row? About 0.1%. A hundred times? Vanishingly small - yet never mathematically impossible.

Determinism and Coin Flips

Some physicists argue that a coin flip is not truly random - it's deterministic. If you could measure the exact force, angle, air resistance, and surface properties, you could predict the outcome every time. In practice, these variables are impossible to control with sufficient precision, making the result effectively random for all practical purposes. But the thought experiment is intriguing: a perfectly engineered flip could, in theory, always produce heads.

A Custom Decision Tool

You don't have to use "Heads" and "Heads". Replace the labels with any two options - "Pizza" and "Sushi", "Go out" and "Stay in", "Yes" and "No" - and use it as a quick, impartial decision-making tool. The coin is fully customisable.

The Probability of N Heads in a Row

The probability of getting heads n times consecutively on a fair coin is (½)ⁿ. For context: 10 in a row ≈ 0.098%, 20 in a row ≈ 0.0001%, 50 in a row ≈ 1 in 10¹⁵. These numbers make clear why sustained "only heads" is essentially impossible in practice - even though each individual flip is always a clean 50/50.

Frequently Asked Questions

With a fair coin, the probability of n heads in a row is (0.5)ⁿ - exponentially small but never exactly zero. Getting 10 heads in a row happens roughly once in every 1,024 attempts. Getting 100 in a row is effectively impossible in a human lifetime.
Yes! Change either or both input fields to any text. Use it as a custom binary decision maker - "Stay" vs "Go", "Tea" vs "Coffee", or any two options you want to decide between randomly.
Determinism is the idea that if all physical variables (force, angle, spin, air resistance) were perfectly controlled, the outcome would be predictable. In reality, those variables cannot be measured or controlled precisely enough, so coin flips remain functionally random.
The underlying flip logic is identical - 50/50 random selection. The difference is that both labels are set to "Heads" by default, so every result shows "Heads". It's a playful way to explore what a biased or trick coin would look like.