Calculators
Random Number Generator
Generate secure random whole numbers in any range locally in your browser.
Enter a minimum and maximum from -1000000000 to 1000000000 and a count from 1 to 100. For example, 1 to 6 with a count of 2 rolls two dice. Numbers are drawn with your browser's Web Crypto API; nothing is uploaded or stored.
Pick random numbers without uploading anything.
Enter a minimum, a maximum, and how many numbers you need to draw secure random whole numbers with your browser Web Crypto API. Everything runs locally in your browser, so your values are not uploaded or stored.
Frequently Asked Questions
Everything you need to know about this tool, how it works, and privacy.
What does the random number generator do?
Enter a minimum, a maximum, and a count from 1 to 100. The generator draws that many random whole numbers between the minimum and maximum, including both endpoints. For example, 1 to 6 with a count of 2 rolls two dice.
How random are the results?
Each number is drawn with your browser Web Crypto API using rejection sampling, which avoids the bias of a simple modulo operation. Results are suitable for games, draws, and sampling, but review your application requirements for high-risk uses such as cryptography or gambling.
What does unique numbers only mean?
When unique numbers only is enabled, no value repeats in one draw. The count must fit inside the range: a range of 1 to 6 holds 6 unique whole numbers, so a count above 6 shows a clear error instead of a result.
Which inputs are accepted?
Enter whole numbers for the minimum and maximum from -1000000000 to 1000000000, with the minimum less than or equal to the maximum, plus a whole-number count from 1 to 100. Decimals, text, and values outside these limits show a clear error instead of a result.
Do my numbers stay private?
Yes. Generation and copying run locally in your browser. CodeASystem does not upload or store the values you enter or generate.