Random Number Generator

How to Use the Random Number Generator

Set the minimum and maximum of your range, choose how many numbers to generate, and decide whether duplicates are allowed. Click Generate and the results appear instantly. To simulate a single die, use 1 to 6 with a count of 1; to draw raffle winners, set the range to your ticket numbers and turn off duplicates so no ticket wins twice.

How Random Number Generation Works

The generator calls the browser's Math.random(), which returns a floating-point value in the range [0, 1). To map that onto whole numbers within your bounds it applies min + Math.floor(r × (max − min + 1)). The + 1 makes the maximum reachable, and Math.floor keeps every integer equally likely. Each generated value is an independent draw, so past results never influence the next one.

Pseudorandom vs. True Random

A computer produces pseudorandom numbers: a deterministic algorithm seeded from an internal state that only appears random. For games, sampling, and picking winners this is indistinguishable from chance. It is not suitable, however, for anything where predictability could be exploited — passwords, session tokens, or gambling with real stakes. Those require a cryptographically secure generator such as crypto.getRandomValues().

Common Uses

Random numbers drive tabletop and video games (dice, loot drops, card shuffles), decide contest and giveaway winners fairly, select random samples for surveys or A/B tests, and settle everyday choices like who goes first. Teachers use them to call on students at random, and developers use them to seed test data. Everything runs locally in your browser, so no results are logged or transmitted.