Where these numbers come from
Every roll on these pages calls your browser's Web Crypto API, the generator the web uses for encryption keys. It is a cryptographically secure PRNG: deterministic arithmetic at its core, but constantly reseeded from physical entropy your device gathers, things like timing jitter and hardware noise. The result is output nobody can predict, including us, because nothing is computed on a server. Your device rolls; we never see it.
One detail worth bragging about: the raw random values are mapped onto dice faces with rejection sampling rather than a simple modulo. The lazy way makes low numbers a whisker more likely. Ours redraws instead, so a d20 gives every face exactly a 5% chance. The lottery picks elsewhere on this site work differently on purpose: they use a seeded daily generator so your numbers hold still all day, where these tools give you a fresh throw every single tap. How random is random sets the two side by side.
- crypto.getRandomValues, the browser's cryptographic generator
- Entirely in your browser; no server ever sees a roll
- None: rejection sampling, every outcome equally likely
- Each throw is independent; past results change nothing
- Kept on your device only, with a clear button
- Replay the exact result; a fresh roll replaces it
Pick a die to roll
d4
The caltrop
Four faces, lands on a point, never rolls far.
Roll a d4 →
d6
The classic
The die everyone means when they say dice.
Roll a d6 →
d8
The octahedron
Two pyramids glued base to base.
Roll a d8 →
d10
The odd one out
The only die in the standard set that isn't a Platonic solid.
Roll a d10 →
d12
The dodecahedron
Twelve pentagons; the Greeks thought it mapped the heavens.
Roll a d12 →
d20
The icosahedron
Twenty triangles, and the most famous die in gaming.
Roll a d20 →
Pick a range and draw
Five thousand years of rolling things
Dice are older than writing about dice. Randomness was a tool long before it was mathematics.
The earliest dice were knucklebones, the ankle bones of sheep and goats, tossed for games and for divination across the ancient Near East. Purpose-made dice followed fast: four-sided throwing sticks in the Royal Game of Ur around 2600 BC, and cubic dice in the Indus Valley at roughly the same time. For most of that history, a die was a way of asking the gods a question. The mathematics arrived embarrassingly late: not until the 1650s, when Pascal and Fermat traded letters about a gambling dispute, did anyone work out how to calculate the odds of a throw.
And one honest note
No generator, this one included, can make a number lucky. What a good one can do is make a number fair: drawn with equal chances, immune to thumb-on-the-scale, the same for a stranger as for a friend. That is the whole promise of these tools. If you want numbers with a story attached, from your birth date rather than from entropy, the rest of this site is exactly that.
Random numbers — frequently asked
It uses your browser's cryptographic generator (the Web Crypto API), the same source that secures encryption keys. Strictly speaking that is a CSPRNG, an algorithm seeded with physical entropy your device collects, rather than a hardware true-random source. For dice, raffles and picks the distinction has no practical effect: the output is statistically uniform and computationally unpredictable.
A pseudorandom number generator (PRNG) is deterministic arithmetic: feed it the same seed and it replays the same sequence forever. True randomness comes from physical measurement, like electrical noise or radioactive decay. Between them sits the cryptographically secure PRNG these tools use, which is regularly reseeded from your device's physical entropy, so no observer can predict the next output.
Dice for game nights and anything with a familiar shape, the coin for yes-or-no calls, the number picker for giveaways and any custom range, the lotto draw when you need a full line of unique sorted numbers, and the picker wheel when the entries are names rather than numbers and people want to watch the draw happen. They all share the same generator underneath; the difference is only how the result is dressed.
Your roll history is saved in your own browser and never leaves it. Nothing is sent to a server, because nothing is computed on one. Each result also gets a link you can copy; the numbers live in the link itself, not in a database.
Because real randomness clusters. A fair d20 repeats its previous face one time in twenty, and a coin lands the same way twice half the time. Streaks feel wrong to human intuition, which expects randomness to look evenly spread. Statisticians actually use suspiciously streak-free data as a sign that results were made up.