97 · Productivity

Random Number Generator

Pick a range and how many numbers you need. Results come from your browser’s cryptographically secure generator, so every number in the range is equally likely.

Uses your browser’s cryptographically secure random generator.

How to use the random number generator

  1. Set the minimum and maximum (both included).
  2. Choose how many numbers to draw.
  3. Tick No repeats for raffles and draws where each number can only come up once.
  4. Select Generate, or tap a preset like dice or a coin flip.

Is it really random?

The numbers come from the Web Crypto API, the same source browsers use for encryption keys. Rejection sampling avoids the small bias that simpler methods introduce, so every value in your range has the same chance.

Using it for draws

For a raffle, number your entries from 1, set the maximum to the number of entries, and turn on No repeats. For transparency in public draws, consider generating the result live in front of participants.

Examples

Between 1 and 100

A single number such as 42

6 unique numbers from 1 to 49, sorted

e.g. 3, 11, 19, 27, 38, 44

Questions

Are the minimum and maximum included?

Yes. A range of 1 to 6 can return 1, 2, 3, 4, 5 or 6.

How many numbers can I generate?

Up to 1,000 at a time. With No repeats on, you can’t ask for more numbers than the range contains.

Can I use decimals?

No, only whole numbers. Divide the result if you need decimals, for example 1–1000 divided by 10 gives 0.1–100.