Random number generator

Enter a range, for example 1 to 100. Both ends are included, so 1 and 100 can come up. Every whole number in the range has exactly the same chance. The numbers come from your browser's cryptographic random number generator (the Web Crypto API), and the tool uses an unbiased method to map them into your range, so no number is favored.

Many simple generators use a formula that slightly favors some numbers when the range doesn't divide evenly into the generator's output. This one rejects those uneven values and draws again, which removes the bias. For no-repeat draws from ranges up to 200,000 it uses a partial Fisher–Yates shuffle, the same method used to shuffle a deck of cards fairly.

No repeats (the default) works like drawing numbered balls from a bag: once a number is drawn, it can't come up again in the same batch. Use it for raffles, lottery-style picks, random samples and assigning unique numbers. You can't ask for more numbers than the range contains; 1 to 10 gives at most 10 unique numbers.

Untick it to allow repeats, which works like rolling a die again and again. Use that for simulations, dice games or random test data.

Range	Typical use
1–2	Coin flip substitute
1–6	One die
1–10	Quick pick, ratings
1–20	Tabletop games (d20)
1–50	Class roster numbers
1–100	Percent chance, guessing games
1–1,000	Raffle tickets
0–9	Single random digit

Negative numbers work too: −10 to 10 gives a random integer around zero.

• Raffle or door prizes: enter the ticket range and the number of prizes, with no repeats.
• Random samples: pick 30 rows out of 2,000 for a survey or audit.
• Teaching: generate practice problems or call on students by roster number.
• Games: guess-the-number, bingo calling or deciding who goes first.
• Shuffling an order: set the range to 1–N, ask for N numbers without repeats and you get a random order of 1 to N.

For dice with animation, use the dice roller; for lottery formats like Powerball, use the lottery number generator.

You can generate up to 10,000 numbers at a time, and the range can go up to 15-digit numbers. Results are shown with thousands separators, and the copy button gives you a comma-separated list you can paste into a spreadsheet. Everything happens in your browser; the numbers are never sent to a server.

Because nothing is stored, a new batch is completely independent of the last one. If you need to prove a draw was fair later, for example for a public raffle, record the screen while you generate, or use the giveaway picker, which produces a verifiable seed and a PDF record.