Random Number Generator

How the numbers are generated

This generator uses your browser's cryptographic random source (crypto.getRandomValues), the same one used to create encryption keys. It is far less predictable than the basic random functions in most programming languages, and every number in the range has an equal chance of being picked.

Common uses

• Prize draws and giveaways: number your entries and draw winners with "No repeats" turned on.
• Lottery-style picks: for 6 numbers from 1 to 49, set the range to 1–49, count to 6, and turn on no repeats and sorting.
• Dice and games: 1–6 for a die, 1–20 for a D20.
• Random sampling: choose survey participants or items to audit from a numbered list.
• Teaching probability: generate 1,000 coin flips (range 0–1) and count how close you get to 50%.

Is it truly random?

Computer randomness comes from a cryptographically secure pseudo-random number generator seeded with unpredictable physical events, such as hardware timing noise. For all practical purposes, including fair draws, it is indistinguishable from true randomness. For regulated gambling or legal lotteries, certified hardware generators are required.

Odds of a draw

The chance of matching all 6 numbers picked from 49 is 1 in 13,983,816. In general, the number of possible combinations of k numbers from n is n! ÷ (k! × (n − k)!).