Dice Roller and Coin Flip
Roll one or more dice, or flip a coin — both with cryptographically secure randomness, right in your browser.
How to use the dice roller and coin flip
- Choose how many dice or coins you want to roll or flip.
- Press the button — the result is shown instantly, and the sum of the dice is calculated automatically.
Is this fairly random?
Yes — both use the browser's cryptographically secure randomness function (crypto.getRandomValues()), the same type of randomness used for security keys, instead of the weaker Math.random() many simpler dice tools use.
Why random rarely feels random
Flip a coin twenty times and you will very likely get a run of four or five identical results somewhere along the way. Most people experience that as something being wrong with the coin, because we expect randomness to look evenly distributed. It does not — genuinely random sequences cluster, and a sequence without clusters is actually a sign that the numbers are *not* random.
The other common fallacy is believing an outcome is «owed». After five heads in a row, the probability of tails is still exactly fifty percent — the coin has no memory, and the five preceding flips do not influence the next one at all. This is known as the gambler's fallacy, and it is just as widespread with dice as with coins.
It is also worth knowing that a digital roll and a physical one are random in different ways. A thrown die is deterministic in principle — given perfect knowledge of the throw you could predict it — but so sensitive to initial conditions that it is unpredictable in practice. A computer uses a pseudorandom generator, which produces a sequence that passes statistical tests for randomness but is generated by a formula. For games and everyday draws the distinction makes no practical difference; for cryptography it matters a great deal, and dedicated generators are used instead.
Frequently asked questions
How many dice can I roll at once?
Up to 20 dice or 20 coins at a time — more than enough for most board games and games of chance.
Can I use this for anything involving real money or stakes?
This tool is built for games, board games and casual use. Games with real money stakes have separate requirements for licensed, audited random number generation (RNG) that this tool isn't certified for.
Are the results stored anywhere?
No, everything happens locally in your browser and isn't stored.