How to use the random number generator
- Minimum and Maximum: the lowest and highest value you will accept. Both ends are included, and negative numbers and decimals work.
- How many numbers: from 1 to 1000 in one run.
- Decimal places: 0 gives whole numbers. Choose 1 to 6 for values such as 47.30.
- No duplicates makes every number appear once, like drawing tickets from a hat. Sort lowest to highest puts the list in order, and Separate with sets commas, spaces or new lines.
- Press Generate numbers, then Copy numbers. The page draws one number from 1 to 100 as soon as it loads.
The Dice roller tab rolls 1 to 10 dice, from d4 to d100, and adds them up. For heads or tails use the coin flip, or the full dice roller for more options.
How the numbers are chosen
The tool asks your browser for random bytes with crypto.getRandomValues, the Web Crypto source that your operating system seeds. It keeps only the values that fall inside your range and throws the rest away, which is called rejection sampling. That avoids the small bias you get from taking a remainder, so every number in the range has exactly the same chance. With No duplicates on, numbers are drawn without replacement, the way you would deal cards.
Worked example
With the opening settings (Minimum 1, Maximum 100, How many 1, 0 decimal places) the result is one whole number from 1 to 100, and each of the 100 values has a 1 in 100 chance, so the number you see differs every time. For a lottery-style pick, set Maximum to 49, How many to 6, and tick No duplicates and Sort lowest to highest. You get six different numbers in order, for example 4, 11, 19, 27, 33, 46.
Limits and edge cases
- Minimum and Maximum can be any value from -999,999,999,999,999 to 999,999,999,999,999, with Minimum not above Maximum. If either has more decimals than Decimal places, it is rounded inward and the result line says so.
- With No duplicates on, the range must contain at least as many values as How many. For example, 1 to 10 has 10 whole numbers but 91 values when you pick 1 decimal place. The message tells you how many values your range holds.
- Random does not mean evenly spread. A short run can repeat a number or cluster, and that is normal.
- Nothing is saved or sent anywhere. For passwords, use the password generator instead, and to pick a person from a list use the random name picker.
Frequently asked questions
Are the numbers from this generator truly random?
They come from your browser's cryptographically secure random generator, crypto.getRandomValues, which is seeded by your operating system. It is not a physical noise device, but its output is unpredictable in practice and far stronger than Math.random(), so it suits games, raffles, sampling and picking winners.
Can the same number come up twice?
Yes. By default each number is drawn independently, so repeats are normal, just like rolling a die twice. Turn on No duplicates to get every number only once. That needs a range with at least as many possible values as the How many field.
How do I get a random number between 1 and 10?
Set Minimum to 1 and Maximum to 10, leave How many at 1 and press Generate numbers. Both ends are included, so 1 and 10 can each come up. The same steps work for any range, including negative numbers.
Can it generate random decimals?
Yes. Set Decimal places to 1 through 6. A range of 0 to 1 with 2 decimal places can return 0.00, 0.01, and so on up to 1.00, and every one of those 101 values is equally likely.
Is it fair to use for a raffle or giveaway?
Every number in the range has the same chance, so it is fair for picking a ticket number. Number each entry first, set the range to match, and keep a screenshot of the result. It is not an audited draw, so do not use it for legally regulated lotteries.