Random Number Generator, Coin Flip & Dice Roller

Random numbers, coin flips and dice in one place

This page combines three tools people reach for every day: a random number generator, a coin flip and a dice roller. Switch between them with the tabs at the top; each keeps its own settings and history.

All results come from your browser’s cryptographically secure random number generator, the same kind used for passwords and encryption, so every number, side and face has exactly the same chance.

Random number generator

Enter a minimum and maximum, choose how many numbers you need and press Generate. Want to pick a number between 1 and 100? Use the quick range buttons. Turn on No repeats to get unique numbers, for example for raffle tickets or lottery-style picks like 6 numbers from 1–49, and Sort results to list them in order.

You can draw up to 1,000 numbers at once, use negative ranges and copy the results with one click. A single number is revealed with a short rolling animation; larger sets appear as a list.

Flip a coin: heads or tails

Press Flip or tap the coin to toss it in 3D. The result is announced as heads or tails and added to the statistics: number of heads and tails, percentages, total flips and the longest streak. The coloured strip shows your last 100 flips.

Need many tosses at once? Use × 10 or × 100 to flip instantly and watch the percentages move towards 50/50, a quick demonstration of probability for classrooms.

Online dice roller

Choose up to 10 dice and the number of sides: classic six-sided dice with pips, or d4, d8, d10, d12 and d20 for board games and tabletop RPGs such as Dungeons & Dragons. Press Roll to shake and throw them; the total is calculated automatically and every roll is kept in the history.

How random is it?

Results use crypto.getRandomValues with rejection sampling, so there is no modulo bias: in a range of 1–6 every value has precisely a one-in-six chance. Unique numbers are drawn with a Fisher–Yates selection. Nothing is pre-set or predictable, and animations are only for show.

Ideas for using it

• Games: replace lost dice, roll a d20, decide who starts.
• Decisions: heads or tails between two options.
• Raffles: draw ticket numbers without repeats.
• Classrooms: pick a student number, teach probability with 100 coin flips.
• Lottery-style picks: six numbers from 1–49 for fun.
• Testing and sampling: choose random rows or IDs from a numbered list.

Keyboard shortcuts and fullscreen

• Space or Enter: generate, flip or roll on the open tab
• Enter in a number field: applies the value and generates
• Fullscreen button: large numbers, coin or dice for projectors and streams
• Address: open #coin or #dice to land directly on a tab

Privacy

Everything runs in your browser. Settings, history and coin statistics are stored only on this device (localStorage) and never sent anywhere.

Frequently asked questions