How Random Number Generation Works
A random number generator (RNG) produces numbers that cannot be reasonably predicted.
This tool uses JavaScript's built-in Math.random() function — a pseudo-random
number generator (PRNG) seeded by the browser — to produce numbers uniformly distributed
within your chosen range.
The formula used is: Math.floor(Math.random() × (max − min + 1)) + min
This guarantees that every integer between your minimum and maximum value has an equal probability of being selected. All generation happens instantly in your browser — no data is ever sent to a server.
Common Use Cases
- Games & contests — Pick a winner from a group by assigning numbers.
- Decision making — Let chance settle a tie or make a fair choice.
- Statistics & education — Generate sample data for experiments.
- Lotteries & raffles — Draw random ticket numbers.
- Passwords & tokens — Seed a random component in a secure token.
Unique vs. Duplicate Numbers
When Unique numbers only is enabled, no number will appear more than once in the result set. This requires that the count you request is no larger than the total range (max − min + 1). When duplicates are allowed, the same number may appear multiple times — just like rolling a die twice and getting the same face.