Coin Flip

How it works

This coin flip tool uses the Web Crypto API (crypto.getRandomValues) for cryptographically secure randomness, not Math.random. Each flip is an independent, unbiased 50/50 outcome. The tool tracks your flip history and shows running statistics.

Everything runs locally in your browser. No data is sent to a server, and no flip results are stored anywhere beyond your current session.

Frequently asked questions

Is each flip really a fair 50/50?

Yes. Each flip reads one random byte from crypto.getRandomValues and calls it heads when the value is below 128 and tails otherwise. That split is exactly even across the 256 possible byte values, so there is no bias toward either side and every flip is independent of the ones before it.

Why does the heads percentage rarely land on exactly 50%?

Fair flips still cluster unevenly over small samples, so a few flips can read 70% heads without anything being wrong. The percentage tends to drift toward 50% as your total grows, which is why the running count is more meaningful after many flips than after just a handful.

Why does the history only show some of my flips?

The history strip displays the most recent 20 flips to keep the layout readable, but the Heads, Tails, and Total counters include every flip in the session. When you flip multiple at once, all outcomes are added to the stats while only the final flip is shown on the coin.

Can I flip more than one coin at a time?

Yes. Enter a number from 1 to 100 in the count field and press Flip Multiple to run that many independent flips in one action. The stats and history update for the whole batch, and the coin face shows the result of the last flip in the batch.

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