Coin Flip Generators
Flip a virtual coin — once, or a thousand times.
Coin Flip is a free online tool that flip a virtual coin — once, or a thousand times. It runs entirely in your web browser using plain JavaScript, so files are processed on your own device and never uploaded to a server. There is no sign-up, no file size limit imposed by the site, no watermark and no paid tier.
- Price
- Free — no account, no quota, no watermark
- Category
- Generators
- Where it runs
- In your browser, on your device
- Files uploaded
- None
- Technology
- plain JavaScript
- Settings
- 2
- Works offline
- Yes, after the first visit
About Coin Flip
The result comes from `crypto.getRandomValues`, the browser's cryptographically secure generator, rather than `Math.random` — which is fast but not uniform enough to be trusted for anything where the outcome matters. A real coin, incidentally, is not quite fair either: a 2007 Diaconis, Holmes and Montgomery analysis found a caught flip lands on the same face it started roughly 51% of the time.
How to use it
- Enter number of flips and flip again.
- Results update the moment anything changes.
The 2 settings
| Setting | What it does | Default |
|---|---|---|
| Number of flips | Range 1–10000. | 1 |
| Flip again | On or off. Off by default. | Off |
Under the hood
| Runs on | plain JavaScript — runs the whole thing |
| Controls | Number of flips, Flip again |
Questions
Is this genuinely random?
It draws from the operating system's entropy source through WebCrypto — the same generator used to produce cryptographic keys. For deciding who buys lunch, comfortably more than sufficient.
Why did I get six heads in a row?
That happens once in 64 sequences, so with any real number of flips it is expected. Runs feel unlikely but are entirely normal; expecting them to be rare is the gambler's fallacy.
What are the limits on number of flips?
It accepts 1 to 10000, starting at 1.