Random Number Generator guide
Generate one or more random integers from an inclusive range, with an optional no-repeat rule.
What this tool does
The Random Number Generator accepts integer minimum and maximum values, a count from 1 to 1,000, and an optional uniqueness requirement. Both range endpoints are included. When uniqueness is enabled, a generated value cannot appear twice and the requested count cannot exceed the number of available integers.
Random values come from the browser's cryptographic random-value interface. The calculator uses rejection sampling before mapping an unsigned 32-bit value into the selected range, avoiding the simple modulo bias that appears when the source range is not evenly divisible by the target range.
The inclusive range is limited to at most 4,294,967,296 integers. Results can be copied one per line. Although the browser source is suitable for many security-sensitive building blocks, this general-purpose interface is not a password, encryption-key, lottery-certification, regulated-drawing, or audited gaming system. Those uses require purpose-built generation, logging, controls, and independent verification.
How to use it
- Enter integer minimum and maximum values.
- Choose how many numbers to generate.
- Enable Do not repeat a number when sampling without replacement.
- Select Generate numbers.
- Review the results and copy them one per line if needed.
Each click creates a new draw. The tool does not accept a seed and cannot reproduce a previous sequence. Save the output if an exact record is important.
After generating a non-sensitive numeric sample, use the Statistics Calculator to inspect its mean, median, range, variance, and standard deviation.
Benefits
- Includes both minimum and maximum values
- Generates up to 1,000 integers at once
- Supports sampling with or without replacement
- Uses rejection sampling to avoid modulo bias
- Relies on the browser's secure randomness source
- Sends no range or result to a server
Fairness and accountability
A technically random sequence does not by itself create a fair process. Participant lists, range assignment, exclusions, redraw rules, device integrity, and recordkeeping also matter. For contests, research allocation, audits, or regulated activities, follow the applicable rules and use a system with appropriate oversight.