Is this random or pseudo-random?

Pseudo-random in the physical sense — the numbers come from your operating system's CSPRNG, a deterministic algorithm seeded from hardware entropy. For picking raffle winners, dice or test data, that is as good as random gets in software.

What does no repeats actually do?

Samples without replacement, so every value appears once. It needs room: the count cannot exceed the size of the range, and the tool says so instead of failing.

Are the results really uniform?

Yes. Rejection sampling throws away the residues that make modulo arithmetic bias the low end of a range, so each value in the range is equally likely.

Can I use the output for a password?

Not really — a number in a range carries a few bits. Use the password generator, which draws from a large alphabet and reports the entropy.

Calculators & Converters Ready to use

Random Number Generator

Draw random integers from any range — one number or a batch, with no repeats and sorting — using the browser's cryptographic RNG, not Math.random.

Mode

Minimum

Maximum

How many numbers

No repeats (unique)

Sort results

This tool runs entirely in your browser. Your input never leaves your device.

About Random Number Generator

Pick a minimum and a maximum and draw one value or up to a thousand at a time. Switch on 'no repeats' and every number in the sample is distinct, drawn without replacement from the range; switch on sorting and the result comes back in ascending order, which is what a lottery line or a raffle ticket list needs.

The draw uses crypto.getRandomValues with rejection sampling rather than Math.random(). Two reasons. Math.random is not required to be unpredictable, so a value someone else might be betting on should not come from it. And `min + Math.random() * (max - min)` rounded, or any `% range`, is not uniform: it quietly favours some outcomes. Rejection sampling discards the biased part of the space and returns a genuinely flat distribution. Dice, coin flips and lottery presets are on the same page for the same reason.

Uniqueness is bounded by the range — asking for 50 distinct numbers out of 1 to 20 is refused rather than silently looping forever. Even with a CSPRNG, treat the output as fair random draws, not as a secret: for a key or token use the password generator instead.