Flip a Coin
One toss, or a rule agreed on before you start
For a quick casual choice, use the default single flip. If a group prefers a series, select best of 3 or best of 5 first. The target is fixed at the start, so a losing side cannot extend the same round after seeing its result. A new round is a fresh decision and clears the previous flips.
For example, assign Heads to Cook and Tails to Takeout, then choose best of 3. The sequence Tails, Heads, Tails finishes with Takeout winning 2–1. Heads, Heads finishes after just two tosses. There is no need for a third toss once a side has won.
Keep the decision and the flips together
Optional names stay attached to their sides for the whole round. The score and numbered list show only that round, so earlier decisions are not mixed into the result. Copy result includes the original rule, names, ordered flips, score and winner. If you change your mind about the rules, use New round rather than editing a finished result.
What makes each side equally likely?
The browser supplies a random byte from 0 to 255 using Web Crypto. This tool maps the 128 even values to Heads and the 128 odd values to Tails. It does not add weights, force alternation or rebalance after a streak. Side names are only labels and never enter the random calculation.
Equal chance applies to each toss, not to the final appearance of every small sample. Two heads in a row, or a best-of-5 round ending 3–0, are possible outcomes. Extending a round until you get a preferred result changes your decision rule; it does not correct the randomness.
For informal decisions, not certified drawings
Web Crypto uses a cryptographically strong pseudorandom generator supplied by the browser. This page is not independently audited or certified, and a copied receipt can be edited. Use it for casual choices or classroom games—not regulated prize drawings, gambling, security credentials, or decisions with serious consequences.
The tool does not upload or store your names and flip history. They stay in the current page unless you copy them. Site analytics and advertising are separate and may still run. If the browser cannot provide Web Crypto randomness, the tool reports the problem instead of substituting another generator.
Frequently asked questions
How do I flip a coin online?
Press Flip coin for an instant Heads or Tails result. Single flip is ready by default. Press Flip again for a fresh one-toss round. If you want a series, choose Best of 3 or Best of 5 before the first flip.
How does best of 3 or best of 5 work?
Best of 3 stops as soon as one side wins twice; it can take 2 or 3 flips. Best of 5 stops at 3 wins and takes 3 to 5 flips. You flip each coin yourself. Once there is a winner, choose New round to start over—the tool will not add extra flips to a finished series.
Can I assign my own choices to heads and tails?
Yes. Open Name the choices before you flip. Enter up to 40 characters for each side, such as Cook and Takeout. Blank names fall back to Heads and Tails. Names do not change the random selection. The rule and names lock after the first flip; New round clears the result and unlocks them.
Is the coin flip random and fair?
Each toss gets a fresh byte from your browser's Web Crypto getRandomValues method. Even values mean Heads and odd values mean Tails: 128 of the 256 possible values map to each side. There is no weighting or adjustment based on previous flips. This is a browser pseudorandom process, not an independently certified drawing or a physical coin.
Why did I get heads several times in a row?
Equal probability does not mean alternating results or exactly half heads in a short run. Every flip uses a new random byte; earlier flips do not make the other side due. With equal independent flips, a specified sequence of three heads has a probability of 1 in 8.
Can I save or share the result?
After a completed round, Copy result copies the chosen rule, side names, every flip in order, score and winner. View decision receipt also provides selectable text if clipboard access is blocked. The receipt is editable plain text, not a tamper-proof record. This tool does not save or upload your choices or flip history; reloading clears them. Normal site analytics and ads may still load.
Can I flip with the keyboard?
Yes. Tab to Flip coin and press Enter or Space. Only the focused button responds; typing a choice name does not flip a coin. Holding a key does not repeatedly flip. JavaScript and Web Crypto support are required; if secure randomness is unavailable, the tool gives no result.