No upload, 100% local, no account

Random Number Generator

Instant, secure, and completely offline, your numbers never leave your device.

How Random Number Generator works

The Random Number Generator produces one or thousands of random integers within any range you define, from a single lottery number to a list of unique IDs. Each number is drawn from the Web Crypto API (crypto.getRandomValues), backed by your operating system cryptographically secure entropy source, far stronger than the predictable Math.random().

It also offers a no-duplicates mode (unique values via rejection sampling, ideal for raffles or sampling), ascending/descending sorting, and bulk generation with one-click copy. The generation logic is separated from browser APIs, making it auditable and deterministic under test.

Frequently asked questions

Does this tool send my numbers or inputs to a server?

No. Everything runs in your browser using JavaScript and the Web Crypto API. No network request is made and it works offline once loaded.

How random are the numbers?

They use crypto.getRandomValues, backed by your OS cryptographically secure RNG, far stronger than Math.random(), which is predictable.

What does No duplicates mode do?

Each number appears at most once, via rejection sampling. The range must hold at least as many distinct integers as the requested count; the tool validates this.

Can I use it for lottery numbers or a raffle?

Yes. Set the range, enable No duplicates and choose how many you need; the secure source makes the draw fair and unbiased.