Coin Flip & Dice Roller

Flip a coin or roll dice when you need a quick, fair decision. Coins come one at a time or in batches; dice use standard tabletop notation, including advantage and disadvantage.

Coins

How many coins

1 2 3 5 10

Flip to start a history.

Dice

Dice notation NdM plus an optional modifier. Append +A for advantage or -L for disadvantage; Enter rolls.

Use dice notation like 2d6+3, 1d20, 4d6-L or d100.

Private by design. This page has no backend. Every flip and roll comes from your device's own random source. The flip history lives in this tab only and disappears when you leave.

Dice notation, briefly

2d6+3 means two six-sided dice plus 3. The die count and the modifier are optional: d100 is one hundred-sider, 4d6 is four of the classic cubes. Sides can be anything from 2 to 1,000, so 1d7 or 2d13 are fine — useful for the many games that do not stop at twenty.

Advantage and disadvantage

Tabletop conventions: with advantage (+A) each die is rolled twice and the higher face counts; with disadvantage (-L) the lower. 1d20+A rolls two twenties and keeps the better, exactly as a game master would ask.

Why the flips are fair

Each flip draws from crypto.getRandomValues with rejection sampling, so heads and tails are exactly 50/50 and cannot be predicted from previous results — unlike Math.random(), whose internal state can in principle be worked out from a few outputs. The coin history is a convenience for settling best-of-three arguments, not a record.

Common uses

Deciding who goes first, tabletop sessions when the physical dice are missing, classroom probability demonstrations, settling a two-option argument with a fair toss, and generating random yes/no decisions in stand-ups.

How to use the Coin Flip & Dice Roller

Choose a coin flip or a dice roll.
For dice, enter standard notation such as 2d6+3 or d100, or pick a preset.
Roll or flip, and see the individual results and the total.

Frequently asked questions

What does notation like 2d6+3 mean?

Roll two six-sided dice and add three to the total; 'd100' is a single hundred-sided die.

Is the randomness fair?

Yes. Results use your browser's cryptographic random generator for an unbiased outcome.

Can I flip or roll many at once?

Yes. Set the number of coins or dice to roll a whole set in one go.