How to generate random integers with or without repeats

Define the range and the number of results

Use the Random Number Generator for whole-number selection within a range. Minimum and Maximum are both included: entering 1 and 6 makes six possible values, not five. Count is how many values you want returned, rather than the upper endpoint. Write down the purpose of the list before generating it. The interface has minimum, maximum, count and uniqueness controls; it does not offer decimal output, excluded numbers, a saved seed or a named-participant list.

Generate a list using the current controls

Open the tool and set Minimum to 1, Maximum to 6 and Count to 3. Leave Unique numbers off and select Process. The result is three integers between 1 and 6, one per line. A possible list is 2, 2, 5, but you should not expect that particular sequence. Copy the result or use Download result to save it as text. Changing a setting clears the previous output; generate again to obtain a result for the new settings.

Choose whether repeats are allowed

With uniqueness off, a number may appear more than once in the same list. That is allowed behavior, not a conversion error. Enable Unique numbers when you need each value at most once within that result. For the 1-to-6 range, a unique count of 6 returns all six values in an unpredictable order. Requesting 7 unique values is impossible because the range has only 6. The number of available integers is maximum − minimum + 1; use that formula before requesting a unique list.

Understand what a fresh run can change

Uniqueness applies within one generated list. It does not remember earlier runs or prevent a value from appearing again tomorrow. Selecting Process again makes a new draw; a short list may still repeat a previous list by chance. The browser supplies random values through its Crypto API. This tool does not publish an audited draw record, verify participants or certify the fairness of a competition. For a simple classroom exercise or test-data sample, keep the settings with the saved output so its range and repeat rule remain clear.

Check input limits and review the saved list

Enter whole numbers, keep minimum no greater than maximum, and choose a count from 1 to 1,000. The endpoints must lie between −1,000,000,000 and 1,000,000,000. A single-value range such as 5 to 5 can return repeated fives with uniqueness off, or one five with uniqueness on. Review the number of output lines and the selected repeat rule before using the list. Generation happens locally in the browser; saving a text result does not also save an independently verifiable history of the draw.

Sources

• MDN: Browser random values