Random Number Generator

This free random number generator picks numbers, letters and names for you in one click. Use it to choose a number between 1 and 10, draw a set of different numbers, pick a random letter, choose a winner from a list of names or split a group into random teams. It runs in your browser, and nothing you type is sent anywhere.

What the random number generator does

• Number. Set a Min and Max anywhere from -1,000,000,000,000 to 1,000,000,000,000, choose how many numbers you want (up to 10,000), and press Generate. Untick Allow repeats to get all-different numbers, and sort them low to high, high to low or leave them in the order drawn. Switch to Decimals for numbers like 0.37 or 12.605, with 1 to 6 decimal places.
• Pick numbers. Draws a set of different numbers from a range, such as 6 from 1 to 49 or 5 from 1 to 50. You can make up to 20 sets at once and add an extra pick from a separate range.
• Letter. A random letter from A to Z, or only vowels or only consonants, in capitals or lower case. Turn off repeats to get letters that are all different.
• List picker. Paste names or items, one per line (a single line separated by commas works too). Pick one, pick several winners in order, or make random teams by number of teams or by people per team.

How to use it

1. Pick a tab. The Number tab is ready to go with 1 to 100.
2. Change the settings you need. Settings are remembered on this device.
3. Press Generate, or press Space or Enter. In a number box, Enter generates right away. In the list box, Enter starts a new line, so use Ctrl+Enter (Cmd+Enter on a Mac).
4. Press Copy result to copy the result as plain text: numbers separated by commas, teams one line per team.

How to read your result

Under every result is a short line saying exactly what was drawn: the range, whether repeats were allowed, the order and the odds. For a single number from 1 to 100 it tells you each of the 100 values had a 1 in 100 chance. If a request is impossible, such as 20 different numbers from a range that only has 10, you get a plain message saying why instead of a wrong answer.

The History list keeps your last 40 results, saved only in this browser. Clear wipes it.

How fair is it?

Every draw uses your browser’s built-in cryptographic random source, crypto.getRandomValues, rather than the simpler Math.random. Simply taking the remainder of a big random number makes some results slightly more likely than others, which is called modulo bias. This tool uses rejection sampling instead: any random value outside the largest even multiple of your range is thrown away and drawn again, so every possible result has exactly the same chance. Ranges larger than about four billion use 53 random bits, so even the full trillion-wide range is covered evenly.

No-repeat draws, number sets and winners use a partial Fisher–Yates shuffle, the standard way to pick items without replacement so that every possible selection is equally likely. Random teams shuffle the whole list first, then deal people out one at a time like cards, so team sizes never differ by more than one.

Tips

• For a random team generator, choose Make teams and set either the number of teams or the number of people per team. With 10 people and 4 per team you get teams of 4, 3 and 3.
• For a giveaway or classroom draw, tick Remove after pick so nobody can be picked twice across several draws. Restore list brings everyone back.
• Need a random decimal between 0 and 1? Choose Decimals, set Min 0 and Max 1, and pick how many places you want. The ends, 0 and 1, can both come up.

FAQ

Is this random number generator really random?

It uses the same cryptographic random source browsers use for security features, and the method used to fit numbers to your range adds no bias. Results cannot be predicted from earlier ones.

Can it pick numbers without repeats?

Yes. Untick Allow repeats on the Number tab, or use Pick numbers, where every number in a set is always different.

Does it work with negative numbers?

Yes. Min and Max can both be negative, for example -50 to -10. If Min is larger than Max, the two are swapped for you.

Is it free?

Yes. It works on phones, tablets and computers with no account or download.

Want a quick yes-or-no instead? Try our coin flip, or test your luck with numbers in Higher or Lower.