Random Number Generator

How to generate a random number

1. Set the range. Type a Min and a Max — whole numbers from −1,000,000,000,000 to 1,000,000,000,000 — or tap one of the quick ranges.
2. Choose how many. Leave How many at 1 for a single number, or raise it to get a list of up to 10,000.
3. Add options if you need them. More options holds No repeats, the order, numbers to exclude, decimals and the separator.
4. Press Generate (or Space). One number appears in large type; a list appears in a scrolling box.
5. Use the result. Copy, Download .txt or Download .csv, or look back at earlier results in History.

Using it as a random number picker for a group? Press F and the number fills the screen.

Random number generator 1–10, 1–100 and other quick ranges

• 1–10: a quick pick for a short list, a rating or a round of a game.
• 1–100: the classic range when someone says “give me a random number”, and handy for percentages.
• 1–1000: more variety, for example to number entries.
• 1–6 and 1–20: the same chances as a six-sided die or a d20; for real dice with totals and modifiers, use the dice roller.
• 1–3: choose one of three options fairly.
• 0–1 with 2 decimals: a random fraction such as 0.42.

Want to watch the number land? Spin a number wheel instead: on the wheel spinner, Templates → Numbers… fills the wheel with up to 1,000 numbers. To pick people instead of numbers, use the random name picker, and to call a bingo game, the bingo caller.

Random number generator: no repeats and other options

• How many: from 1 to 10,000 numbers in one go.
• No repeats: every number in the list is different, like drawing numbered slips without putting them back.
• Order: keep the draw order, or sort ascending or descending.
• Exclude: numbers that may never come up, for example 13, 20-25; use a..b for ranges with negative numbers.
• Decimals: 0 to 6 digits after the point, on an even grid from Min to Max.
• Separator: new line, comma or space between the numbers you copy or download.

Repeats come up more often than people expect: ask a random number generator 1–100 for 10 numbers, and at least one duplicate shows up about 37% of the time. Turn on No repeats when that matters. To shuffle names or items instead, use the list randomizer.

How the numbers are picked — and is it “true” random?

When you press Generate, this random number generator draws each number with your browser’s secure random generator (crypto.getRandomValues). It uses rejection sampling: a raw random value is kept only if it falls in a range that divides evenly by the number of possible results. That removes the bias of the common “random modulo range” shortcut, which on 1 to 1,000,000,000 would make the first 294,967,296 numbers 25% more likely than the rest. Excluded numbers are drawn again, and No repeats shuffles the possible numbers and takes the first ones. The generator is seeded by your operating system; it is not a hardware random device, but its output can’t be predicted from earlier results. Nothing you enter is sent anywhere.

Random numbers in Excel, Python and on a TI-84

• Excel and Google Sheets: =RANDBETWEEN(1,100) gives a whole number from 1 to 100, and =RAND() a decimal between 0 and 1. Both change whenever the sheet recalculates, so paste them as values to keep them.
• Python: random.randint(1, 100) is fine for games, and random.sample(range(1, 101), 10) gives ten different numbers. For anything that should be hard to predict, use secrets.randbelow(100) + 1, which draws from the operating system’s secure generator, the same kind used here.
• TI-84: press MATH, go to PRB and choose randInt(, then type 1,100) so the line reads randInt(1,100), and press ENTER.

For a quick answer without formulas, generate the numbers here and paste them in. To decide between two options instead, flip a coin.