Random Number Generator
Generate random whole numbers or decimals in any range — one, or a whole list, with or without repeats — from a seed you control, so the same seed always gives the same draw.
The numbers come from a seeded xorshift generator: the seed you type is hashed to start it, so a given seed always produces the same sequence.
How the random number generator works
The numbers come from a seeded xorshift generator: the seed you type is hashed to start it, so a given seed always produces the same sequence. That makes a draw reproducible and shareable — the link carries the seed, so anyone opening it sees the same numbers, which matters if you are drawing a winner or splitting a group and want to be able to prove it later. Change the seed for a fresh draw. For anything where money or security depends on the result, use a properly audited random source, not a web page.
Formula: value = min + ⌊random × (max − min + 1)⌋
Worked examples
| Inputs | Result | Note |
|---|---|---|
| 1 to 100, one number | 84 | the same seed always draws the same number |
| Six lottery numbers, 1–45, no repeats | 15, 19, 21, 37, 1, 31 | a raffle-style draw |
| A decimal between 0 and 1 | 0.081097 | six decimal places |
FAQFrequently asked questions
Why does it ask for a seed?
So the draw can be repeated. The same seed always gives the same numbers, and the page link carries it — useful if you need to show the draw was not re-rolled.
How do I get a fresh set?
Change the seed to anything else — a word, a date, a name.
Is this random enough for a prize draw?
It is fine for picking a winner among friends, splitting teams or sampling. For gambling, security or anything audited, use a certified random source.
Can it pick lottery numbers?
Yes — set the range, the count, and turn repeats off so no number is drawn twice.
What is the largest list?
500 numbers at a time.
Where these figures come from
- NIST Digital Library of Mathematical Functions — reference definitions for elementary and special functions
- Wolfram MathWorld — definitions and formulas for every topic on this page
- NIST/SEMATECH e-Handbook of Statistical Methods — the statistical formulas (mean, variance, z, confidence intervals, sample size)
- Common Core State Standards — Mathematics — the terms and methods taught in US schools
Last checked: September 2026. Formulas are fixed by mathematics and do not change with tax years or regulations.