Picking a number “at random” in your head is a bad idea: people avoid repeats, favour 7 and shy away from the ends of a range. A generator removes those habits, but only if it is built properly.
What is under the hood
The Random Number Generator takes its randomness from the browser’s crypto.getRandomValues, not Math.random. It also uses rejection sampling when it fits a raw number into your range. A plain remainder operation makes some results very slightly more likely than others; rejecting the leftover values keeps every number in the range equally probable. The numbers are produced in your browser and are not sent anywhere.
Using the generator
- Choose the minimum (0, 1 or −100) and maximum (10, 100, 1,000 or 100,000). The minimum must be lower than the maximum, and both ends are included.
- Choose how many numbers you want: 1, 5, 10 or 25.
- Tick unique if no number should repeat.
- Read the list and copy it.
Examples
- Settle a close decision. Number up to ten options, set the range to 1 to 10, generate one number and go with it.
- Pick five winners from 100 entries. Number the entries 1 to 100, choose five numbers with unique ticked, and each entry can win at most once.
- Draw a lottery-style set. Choose unique numbers from 1 to 100 and read as many as you need.
Keeping a draw fair
Fairness is partly about the number and partly about the process. Decide the range and the list of entrants before you generate anything, generate once, and keep the result as it appeared rather than re-rolling until you like it. For public giveaways, say how winners were chosen and keep a record, and check any local rules about prize draws.
When not to use it
The numbers are strong enough for games, sampling and raffles, but a browser tool is not an audited lottery system. For anything with regulatory or large financial consequences, use a process that your jurisdiction recognises. Do not use a generated number as a password; the password generator is built for that.