Random Number Generator

Generate random numbers from any range — single value or bulk

Random numbers come up constantly: rolling dice for a board game when you do not have physical dice nearby, generating test data for a software project, picking a winner from a numbered raffle, choosing a random sample for a research study, generating random IDs for placeholder records, or just shaking off decision paralysis by letting chance pick for you. This Random Number Generator produces one or many random numbers from a custom range in a single click.

How to use it

Enter your minimum value and maximum value (the range is inclusive on both ends — both endpoints can be picked). Choose how many numbers you want generated. Pick options: integer or decimal, allow duplicates or require unique values, sorted or in random order. Click Generate. Numbers appear instantly in the output area, ready to copy.

Integer vs decimal

For most uses you want whole-number integers — dice rolls, lottery picks, test IDs, list indices, sample sizes. The tool defaults to integers. For statistical simulations, percentages, or any case where you need fractional values, switch to decimal mode and specify the number of decimal places (1–10).

With or without duplicates

By default, every generated number is independent of every other — duplicates can and will happen. Generating 100 numbers between 1 and 10 will give you many repeats. If you want unique numbers (sampling without replacement), enable the "no duplicates" option. Note that this only works when the count of numbers you want is less than or equal to the size of the range — you cannot generate 20 unique numbers from a range of 1 to 10.

Real-world uses

Dice rolls for tabletop games. Dungeons & Dragons uses dice of many sizes (d4, d6, d8, d10, d12, d20, d100). Generating a single integer from 1 to 20 simulates a d20 roll perfectly.

Raffle and lottery winners. Number your entrants 1 through N, generate one random number in that range, and that is your winner — auditable, fair, and observable.

Random sampling for research. Pulling a random subset of records from a database for manual review or quality checking. If you have 10,000 records and want to audit 100 of them randomly, generate 100 unique numbers between 1 and 10,000 and audit those records.

Test data generation. Filling out forms during development, populating a database with fake data, or stress-testing a numeric system all benefit from quick random-number generation.

Making decisions. Two equally good options? Generate a 1 or 2 and go with that. It is a surprisingly effective way to break decision paralysis when both options are good enough.

Random pairings. Assign people random partner numbers for a workshop, exercise, or icebreaker.

Random delays for testing. When simulating real-world variability — like a user typing speed or a network delay — random numbers feed the simulation.

Generating unique IDs. Quick placeholder IDs for prototypes, mockups, or test scenarios. Note that for production identifiers you should use a proper UUID generator, not a random number.

True randomness vs pseudo-randomness

Software random number generators are technically pseudo-random — they produce sequences of numbers that pass statistical tests for randomness but are determined by an underlying algorithm. For everyday uses (games, raffles, sampling, decisions), pseudo-random is indistinguishable from "true" random and is what you want. For cryptographic uses (encryption keys, security tokens), you need a cryptographically-secure pseudo-random number generator — and your browser already provides one in window.crypto.getRandomValues, which is what this tool uses under the hood.

True randomness — derived from physical processes like radioactive decay or atmospheric noise — exists and is used in certified random-draw situations (national lotteries, for example), but it is overkill for nearly every practical use. The cryptographic random number generators built into modern browsers are excellent for all but the most extreme applications.

Output formatting

By default, numbers are output one per line, in the order they were generated. You can switch to comma-separated, space-separated, or any custom delimiter. You can sort the output ascending or descending — useful when you have generated lottery numbers and want them in order for display.

Privacy

The generation runs entirely in your browser using the browser's built-in random source. Nothing is sent to a server, nothing is logged, and nothing is stored. Your random numbers are yours alone, and they vanish when you close the tab.