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Coin Flip & Dice Roller
Flip a coin or roll dice from d4 to d100 — fair results from your browser’s cryptographic random generator.
Coin flip
Heads 0 · Tails 0
Dice roller
Truly fair: results come from crypto.getRandomValues, your browser’s cryptographically secure random number generator, with rejection sampling so every face is exactly equally likely. Press Space to flip, or R to roll.
About the Coin Flip & Dice Roller
The Coin Flip and Dice Roller flips a fair coin or rolls any number of dice from d4 to d100, using your browser’s cryptographically secure random number generator. A running history shows your recent results. Use it for board games and tabletop RPGs, quick decisions, classroom probability lessons or settling who goes first.
How to use the Coin Flip & Dice Roller
- Choose coin flip or dice.
- For dice, pick the type (d4, d6, d8, d10, d12, d20 or d100) and how many to roll.
- Flip or roll.
- Check the result and the running history.
Frequently asked questions
Is an online coin flip really random?
Yes. The results come from your browser’s cryptographic random number generator, the same source used for security keys, so every flip is independent and fair.
What does d20 mean?
The “d” stands for die and the number for its sides, so a d20 is a 20-sided die. Tabletop games write rolls like 2d6, meaning two six-sided dice added together.
What are the odds of getting heads three times in a row?
Each flip is 1 in 2, so three heads in a row is 1 in 8, or 12.5%.