Each configured side has an equal probability on every flip. Equal probability does not mean outcomes must alternate or that a short session will contain exactly the same number of each side. Streaks and uneven short samples are normal.
Selection happens before animation
The result comes from crypto.getRandomValues() in your browser. Animation only reveals that preselected result; disabling motion does not change the outcome. There is no silent Math.random() fallback.
Your labels stay local
Custom choices are stored only in this browser so they can survive a refresh. Label text is not placed in the URL and is never attached to product events. Use Restore Heads/Tails to remove it.
Everyday decisions only
Browser Web Crypto provides cryptographically strong pseudo-random values, not proof of physical randomness or an independently audited draw. Do not use this tool as evidence for legal, gambling, prize, or other high-stakes outcomes.
How to flip a coin online
Keep Heads and Tails or enter two custom choices.
Activate the coin or the Flip coin button with pointer, touch, or keyboard.
Read the textual result and review session-only counts, history, and streaks.
Reset statistics whenever you start a new decision.
When a coin toss is the right tool
A coin toss earns its place when the options are close enough that more deliberation is not worth the time, and when both sides need to accept the outcome as unbiased.
Sports and games. Decide who kicks off, serves, bats, breaks, or moves first.
Splitting a chore. Settle who drives, washes up, or takes the early shift.
Breaking a real tie. Pick between two restaurants, two routes, or two equally good options.
Ordering a list. Randomise turn order without anyone choosing it.
Teaching probability. Generate real trial data for independence, streaks, and the law of large numbers.
For a toss both sides have to accept, agree which label belongs to whom before flipping: the announced text is the face the coin lands on, and the published method shows exactly how it was chosen. Need something other than an even split? Use the weighted coin.
Coin flip questions
Is an online coin flip really 50/50?
On this site, yes. Each flip reads one random byte from your browser’s crypto.getRandomValues() and uses its lowest bit, and a byte contains exactly 128 even and 128 odd values, so both sides have identical probability. A physical coin toss is slightly less even: in a 350,757-flip experiment, real coins landed on the side that started facing up about 50.8% of the time.
Is this coin flip random, or is the result decided in advance?
The result is generated the moment you flip, from the operating-system randomness your browser exposes through the Web Crypto API. It is never fetched from a server, never seeded from the time of day, and never taken from Math.random(). The animation only reveals a result that was already selected, so the spin cannot change it.
Can I flip a coin with my own two options instead of heads and tails?
Yes. Open Customize choices under the coin and enter any two labels up to 32 characters, or use the Yes/No and Team A/Team B presets. Labels stay in your own browser, are never written into the URL, and are never attached to product events.
Does a long run of heads mean the coin flip is broken?
No. Independent flips do not alternate, so streaks are expected. Five heads in a row has a probability of 1 in 32, which turns up regularly in a normal session. The Probability Lab runs thousands of flips so you can watch the proportion settle near 50% while individual streaks still appear.
Do I need an account, an app, or an internet connection to flip?
No account and no app. Everything runs inside the page, so after the first load a flip needs no network request at all. There is nothing to install and no sign-up.