How to use the Coin Flip
- Leave flips at 1 for a single heads-or-tails answer, or enter more.
- Press Flip coin.
- Read the result, the heads and tails count and the longest run.
How it works
Each flip takes one random value from your browser's cryptographic generator and turns it into heads or tails, so both sides have exactly a 50% chance and earlier flips never affect the next one.
Real coins are very close to fair but not perfect. A large 2023 study of more than 350,000 hand-tossed flips found coins landed on the same side they started on about 51% of the time. A virtual coin has no such bias.
Streaks are normal. Over 100 flips, a run of six or seven of the same side in a row is common. Believing tails is "due" after several heads is the gambler's fallacy: the next flip is still 50/50.
Formula
Chance of heads = 1 ÷ 2 Chance of k heads in a row = (1 ÷ 2)ᵏ
Example
The chance of three heads in a row is ½ × ½ × ½ = 12.5%. Ten heads in a row is 1 in 1,024, or about 0.1%.
Chance of a streak
| Same side in a row | Chance from a fresh start |
|---|---|
| 2 | 25% |
| 3 | 12.5% |
| 4 | 6.25% |
| 5 | 3.13% |
| 10 | 0.098% (1 in 1,024) |
Frequently asked questions
Is an online coin flip 50/50?
Yes. Each flip here has exactly a 50% chance of heads and 50% of tails, and flips are independent.
What are the odds of 10 heads in a row?
1 in 1,024, about 0.1%.
How does best of three work?
Flip until one side has won twice. It takes two or three flips and gives each side an equal chance overall.
Is it fair to use a coin flip to decide?
For two equal options, yes. Some people find that their reaction to the result shows which option they really wanted.
Last reviewed October 21, 2026. Spotted an error? Tell us.