Random number generator
Set a range and press Generate. Pick one number or a whole list, with no repeats if you need them.
Runs in your browser. What you type is not sent to a server.
How the numbers are picked
Numbers come from your browser's cryptographic random generator (the same source our password generator uses), not from a predictable formula. Every number in the range has the same chance: values that would make some numbers slightly more likely are thrown away and drawn again.
"No repeats" works like drawing balls from a bag without putting them back, so you can't ask for more numbers than the range holds. Without it, each number is drawn independently and the same value can come up twice, like rolling a die.
What people use it for
- Raffles and giveaways: number the tickets or entries, set the range to match, and draw with "No repeats" so nobody wins twice.
- Classrooms: pick a student number, split work into random groups, or choose which question comes next.
- Games: roll one or two dice, flip a coin (heads or tails), or pick a starting player.
- Sampling and testing: choose which rows of a list to check, or generate test values in a range.
The odds behind common picks
| Pick | Chance |
|---|---|
| A given number from 1 to 100 | 1 in 100 (1%) |
| Rolling a 7 with two dice | 6 in 36 (about 16.7%), the most likely total |
| Rolling a 2 or a 12 with two dice | 1 in 36 each (about 2.8%) |
| All six numbers in a 6-from-49 draw | 1 in 13,983,816 |
| At least one repeat when you draw 10 numbers from 1 to 100 with repeats allowed | About 37% |
| The same, with 20 numbers | About 87% |
The last two rows surprise most people, and they are the reason the "No repeats" option exists. Repeats show up much sooner than intuition suggests, the same effect that makes two people in a room of 23 more likely than not to share a birthday.
The sum behind the 37%: the chance that 10 draws from 1 to 100 are all different is 100/100 × 99/100 × 98/100 × … × 91/100, about 0.628. One minus that is 0.372, so roughly 37 times in 100 at least one number repeats. With 20 draws the all-different chance drops to about 0.130, which leaves 87%.
Quick picks and what they show
The buttons above the range fill in the settings and change how the result reads. These are the formats you will see:
| Button | Settings it fills in | Result looks like |
|---|---|---|
| 1 to 10, 1 to 100 | That range, one number | 7, or 53 |
| Roll a die | 1 to 6, one number | 4 |
| Two dice | 1 to 6, two numbers, repeats allowed | 5 + 4 = 9 |
| Flip a coin | 1 to 2, one number | Heads or Tails |
| 6 from 49 | 1 to 49, six numbers, no repeats | Six numbers in order, smallest first |
Two dice allow repeats because real dice can both land on the same face; a double six is 1 chance in 36. The lottery-style pick is always sorted, the way tickets print them. If you change the range or the count by hand, the result goes back to plain numbers. The list of recent results keeps the meaning too, for example "1 + 2 = 3 (1–6) · Tails · 53 (1–100)", so you can tell a coin flip from a number at a glance.
Is it truly random?
Computers can't flip real coins, but the browser's cryptographic generator is built so that its output can't be predicted, even by someone who has seen earlier results. It is the same source browsers use to create encryption keys. A simpler formula, like the one behind many spreadsheet functions, repeats patterns that a determined person could spot.
For draws with legal or financial stakes, such as an official lottery or a regulated prize draw, use whatever process the rules require. This tool is meant for everyday picks where you want a fair result quickly.
Questions
Can I use this for a giveaway or raffle?
Yes. Number the entries, set the range to match, and draw with "No repeats" on. For a list of names, the name picker saves you the numbering.
Can I get decimals or negative numbers?
Negative whole numbers work: set From to -10 and To to 10, for example. The tool picks whole numbers only; for one decimal place, pick from 0 to 100 and divide the result by 10.
Are the numbers saved anywhere?
No. They are drawn in your browser and disappear when you leave the page. The last few results are kept only on this page so you can look back.