How the random-number generator works
The generator uses the browser's cryptographic random-number source when available and maps those values into the selected range. Each allowed integer has an equal chance of being selected.
Unique random numbers
For integers, unique mode samples without replacement, so the requested count cannot exceed the number of integers in the range. Decimal uniqueness is based on the selected precision.
Uses for random numbers
Random numbers can support classroom exercises, sampling, games, test data and fair ordering. This page is not a substitute for audited lottery, gambling or security software.