Random Number Generator
Generate random numbers within any range. Single numbers, sets, dice rolls, or unique random numbers without repetition.
Result
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What is Random Number Generator?
A random number generator produces numbers that have no predictable pattern within a defined range. This tool offers three modes: a single random integer between any two values, a set of multiple random numbers (with or without repeats), and a dice roller supporting standard polyhedral dice from d4 to d100. All results use JavaScript's Math.random() function.
How to use
- 1 Select a mode: Single for one number, Set for multiple numbers, or Dice for a dice roll.
- 2 For Single and Set modes, set the minimum and maximum values of your desired range.
- 3 For Set mode, specify how many numbers to generate and whether repeats are allowed.
- 4 For Dice mode, choose the number of dice and the number of sides per die.
- 5 Click Generate to produce the result — click again for a new random output.
Example calculation
To simulate drawing 6 lottery numbers from 1 to 49 without repetition, select Set mode, set min to 1 and max to 49, enter 6 numbers, enable No repeats, and click Generate. Each click produces a fresh draw of 6 unique numbers from the full range.
Frequently asked questions
Is this truly random?
JavaScript Math.random() produces pseudorandom numbers — sequences that appear random but are generated by a deterministic algorithm seeded by system entropy. For most everyday purposes this is more than sufficient, but it is not suitable for cryptographic security.
What is the difference between the Single and Set modes?
Single mode generates exactly one integer. Set mode generates a list of numbers in one click, with the option to ensure no number appears twice (no repeats mode). Set mode is useful for lotteries, random sampling, and team selection.
Which dice types are supported?
The dice roller supports d4, d6, d8, d10, d12, d20, and d100. You can roll up to 20 dice at once. The result shows each individual die value and the total sum.
Can I generate random decimal numbers?
This calculator generates integers only. For random decimals, you would need a different tool or could divide the integer result by a power of 10 to shift the decimal point.
Why does the no-repeats option sometimes generate fewer numbers than requested?
If you request more unique numbers than exist in the range (e.g., 10 unique numbers between 1 and 5), the calculator caps the output at the size of the available pool. You cannot have more unique values than the range contains.