Coin flip: heads or tails
Heads or tails: one flip or a series, with the results counted.
A single flip and a series
A single flip is an independent event with equal odds: 50% heads, 50% tails. A series of a hundred flips shows not only the outcome but also the tally: how many times each side came up and what share it took. That makes it easier to see that "the coin has no memory" of previous flips — each next one does not depend on them.
What a long series shows
The more flips, the closer the shares get to 50%, but do not expect perfect equality: with a hundred flips a deviation of 5–10 points is normal. That is the law of large numbers at work, not a rigged generator. Short series are useful for exactly that: they show plainly that randomness does not have to look "even".
Fairness of the flip
Values come from crypto.getRandomValues — the same source browsers use for encryption. Math.random() is not suitable here: its sequence is predictable, and for a wager or a prize draw that is fundamental. No server is involved: the flip happens on your device and the result is not sent anywhere.
For drawing lots among people, a random pick from a list is more convenient than a coin — there you can choose several winners without repeats.
Frequently asked questions
Is the coin really fair?
Each flip is independent, with equal odds for heads and tails. The cryptographic generator rules out patterns, but in a short series the count can differ noticeably from 50/50 — that is normal.
Can I flip 1,000 times?
Yes, a series of up to 1,000 flips at a time. We show the number of heads, tails and their shares as percentages.
Why not just use Math.random()?
Its sequence is predictable. For settling an argument with friends that matters little; for a prize draw it is a problem, which is why crypto.getRandomValues is used here.
Related tools
Checked: 26 October 2026. For reference only — the result depends on the material and the skill of the installer.