Random Number Generator
Generate truly random numbers from any range — singles, batches, unique lottery-style draws — using your browser's cryptographic RNG.
Drawn from your browser's cryptographic random number generator (crypto.getRandomValues) — nothing is sent anywhere.
This tool runs entirely in your browser. Your data never leaves your device — it is not uploaded to any server.
How to use
- 1Set the minimum and maximum (both inclusive, negatives welcome).
- 2Choose how many numbers you need and toggle unique draws if repeats would ruin the raffle.
- 3Enable sort ascending for ordered results, or leave it off to preserve draw order.
- 4Copy the list straight into your spreadsheet or raffle announcement.
Random Number Generator
Math.random() is fine for games but biased and predictable. This generator draws from crypto.getRandomValues, your browser's cryptographic random source, with rejection sampling that removes modulo bias — every number in the range is equally likely.
Draw one number between bounds, a whole batch, or unique draws for raffles and giveaways; sort results ascending or keep draw order. The tool also shows the total entropy of the draw in bits, so you can demonstrate a giveaway was fair.
Frequently asked questions
Is this suitable for giveaways and lotteries?
Yes. The numbers come from the browser's cryptographic RNG with an unbiased rejection-sampling step, so each value in the range has the same probability. The entropy readout shows exactly how much randomness went into the draw.
What does “no duplicates” do when the range is small?
It switches to drawing without replacement — like pulling numbered balls from a bowl. If you ask for more unique numbers than the range contains, the tool explains the conflict instead of returning a biased result.
Are the numbers saved anywhere?
No. Everything is computed in your browser's memory from crypto.getRandomValues; reloading the page wipes the results, and nothing is ever uploaded.
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Embed this tool
Put this tool on your own site with one line — it runs entirely in the visitor's browser.
<iframe src="https://zoyku.com/en/tools/random-number?embed=1" width="100%" height="640" style="border:0;border-radius:16px" title="Zoyku — random-number" loading="lazy"></iframe>