CyberCodeRandom Number Generator
Free online random number generator. Pick cryptographically random numbers in any range, generate multiple at once, and optionally exclude repeats — perfect for draws and sampling.
How are fair random numbers generated?
Fairness means every number in the range has exactly equal probability. The naive approach — random() times range — introduces subtle bias. This tool uses rejection sampling over the browser's cryptographically secure generator, the mathematically correct method.
The 'no repeats' mode performs a Fisher-Yates shuffle over the whole range and deals numbers from it, exactly like drawing numbered balls from a bag — the standard for prize draws and random sampling.
How to use
- 01Enter the minimum and maximum of your range.
- 02Choose how many numbers to generate and whether repeats are allowed.
- 03Click Generate.
- 04Copy the random numbers.
Frequently asked questions
- Are these numbers truly random?
- They come from your browser's cryptographically secure random generator (CSPRNG), which is far higher quality than Math.random() and suitable for draws and sampling.
- What does the no repeats option do?
- It guarantees every generated number is unique — like drawing numbered balls from a bag without putting them back.
- Is there any bias toward certain numbers?
- No. The tool uses rejection sampling to ensure every number in your range has exactly the same probability.