Random Number Generator
Generate random numbers in any range, with or without duplicates.
Press Space to generate again.
This tool is for informational and educational purposes only. It is not a substitute for professional financial, medical, legal, or engineering advice. See Terms of Service.
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Request a ToolHow to Use the Random Number Generator
Set your minimum and maximum, choose how many numbers to generate, and click Generate. Results appear instantly.
- Min and Max: Set the range. The generator includes both the minimum and maximum values as possible results. Negative numbers are supported.
- Count: Generate 1 to 1,000 numbers in one click. Large counts display as a comma-separated list.
- No duplicates: Uncheck "Allow duplicates" to ensure every generated number is unique. The count will be capped at the range size if needed.
- Copy: Copy all generated numbers to your clipboard as a comma-separated list.
About Random Number Generation
This generator uses JavaScript's Math.random() function, which produces a floating-point number between 0 (inclusive) and 1 (exclusive). Multiplying by the range size and taking the floor gives a uniform integer in the desired range. Math.random() is a pseudo-random number generator (PRNG) based on the XorShift128+ or Xoroshiro128+ algorithm depending on the browser. It is not cryptographically secure but is perfectly suitable for games, decisions, sampling, and experimentation.
Frequently Asked Questions
How do I generate a random number between 1 and 10?
Set the minimum to 1, the maximum to 10, and the count to 1, then click Generate. Every integer from 1 to 10 has an equal chance of being selected. You can also generate multiple random numbers in the same range at once by changing the count.
Can I generate random numbers without repeats?
Yes. Uncheck "Allow duplicates" before generating. The tool uses a Fisher-Yates shuffle on the full range of possible values and picks the first N items, guaranteeing uniqueness. If you request more numbers than the range contains (for example, 15 unique numbers from 1 to 10), the count is automatically capped at the range size.
Is this tool suitable for research or statistical sampling?
For most research applications, Math.random() provides sufficient randomness. However, it is a pseudo-random number generator and uses a deterministic algorithm seeded by an internal state. For cryptographic applications, security-sensitive selection, or formal statistical research requiring certified randomness, use a hardware random number generator or a service providing true random numbers (such as random.org, which uses atmospheric noise).
Can I generate random decimals?
This tool generates integers only. For random decimals, you can use the generated integers and mentally shift the decimal point (generate 1-1000 and divide by 10 to get 0.1 to 100.0 increments), or open your browser console and type Math.random() to get a random decimal between 0 and 1.