Random number generator — secure and unbiased
Generate random numbers in any range, whole or decimal, with an option to avoid repeats. Uses your browser’s cryptographic generator rather than Math.random.
Runs entirely in your browser — nothing is uploaded.
1 to 1000
Values come from crypto.getRandomValues, your browser’s cryptographic generator — unbiased and unpredictable, unlike Math.random. Suitable for draws and giveaways.
How to use
- Set the range. Minimum and maximum, both included.
- Choose how many. Up to 1,000 at a time.
- Set the rules. Whole numbers or decimals, and whether repeats are allowed.
- Press Generate again for a fresh set. It deliberately does not re-roll while you are adjusting the settings.
Questions
Is this random enough for a prize draw?
Yes. It uses crypto.getRandomValues, the same cryptographically secure source used for keys and tokens, so results are unpredictable and unbiased. Math.random — which most online generators use — is neither.
Can I get the same number twice?
Yes, unless you turn on "No repeats". Genuine randomness produces duplicates: over 10 rolls of a six-sided die, seeing the same face twice is expected, not a fault.
Why can I not get 10 unique numbers between 1 and 5?
Because only five whole numbers exist in that range. The tool tells you instead of looping forever or silently returning fewer.
Are the results logged anywhere?
No. Generation happens in your browser and nothing is transmitted, which is why this is safe to use for a draw you need to be able to stand behind.