Number Randomizer

1. Set the range by entering the minimum and maximum values.
2. Choose how many numbers to generate.
3. Enable "unique" to prevent repeats, and "sorted" to receive them in ascending order.
4. Enter a seed if you want reproducible results.

Without a seed, each run produces a different result. With a seed, the same input always returns exactly the same sequence.

That is useful when a draw must be auditable: you publish the seed beforehand, generate afterwards, and anyone can repeat the process and reach the same result.

It also serves software testing, where reproducing a failing case requires the same sequence of numbers.

The seed is converted into an initial state feeding an xorshift generator — fast, deterministic and suitable for draws and simulation.

A seeded generator is **pseudorandom**: predictable by construction. Anyone who knows the seed reproduces the whole sequence.

That makes it unsuitable for passwords, tokens, keys, verification codes or any value that must be unpredictable to an attacker.

Those cases need cryptographic randomness — which is what this site’s password generator uses.

The distinction is not too technical to matter: high-value prize draws have been defrauded precisely because they used a predictable generator.

With unique enabled, the range must accommodate the requested count. Drawing 10 unique numbers between 1 and 5 is impossible, and the tool refuses rather than looping forever.

Without it, repeats are expected — and more common than intuition suggests. Across 23 draws between 1 and 365, the chance of a repeat already exceeds 50%, the same calculation as the birthday paradox.