Coin Flip — Heads or Tails

Flip a virtual coin and settle it heads or tails.

Flip

How many coins

One for a decision, or many to watch the split even out.

Each flip uses your browser cryptographic random generator, so it cannot be predicted from previous flips. A real coin is very slightly biased toward the face that started upward; this one is not.

What does Coin Flip do?

Flip a coin when you need an honest fifty-fifty decision. The result comes from your browser cryptographic random number generator rather than a predictable pseudo-random sequence, and a running tally of heads and tails lets you check that it really is even over many flips.

How to Use Coin Flip

1
Choose how many coinsOne for a decision, more to see a distribution.
2
FlipPress the button or hit the spacebar.
3
Read the resultHeads or tails, with the running tally underneath.

Key Features

Cryptographically secure randomness, not a predictable pseudo-random sequence
Animated flip with a clear heads or tails result
Flip several coins at once and see the split
Running tally and history of every flip in this session
Keyboard and touch friendly, so it works anywhere

Frequently Asked Questions

Is this coin flip really random?

Yes. It uses the Web Crypto random generator built into your browser, which is the same source used for cryptographic keys. It is not seeded from the clock and cannot be predicted from previous flips.

Is a real coin toss actually 50-50?

Very nearly, but not exactly. Physical studies have found a slight bias — around 51% — toward the side that was facing up before the flip, because of how the coin precesses in the air. A digital flip has no such bias.

I got six heads in a row — is it broken?

No. Six in a row happens roughly once every 64 sequences of six flips, so it is common. Independent flips have no memory, so a run of heads does not make tails more likely on the next flip.

Can I flip more than one coin at a time?

Yes. Set the number of coins and every flip is generated independently, then summarised as a heads-and-tails split. That is useful for probability homework as well as for decisions.