Random number generator
Generate numbers in any range, with or without repeats.
- Runs in your browser — nothing you enter is uploaded
- No sign-up, no quotas, free to use as often as you like
How it works
Random numbers are wanted for draws, sampling, games and picking a winner. Most online generators use ordinary pseudo-random functions, which are predictable enough that they should not decide anything that matters.
It uses a cryptographic source
Numbers come from the browser's own cryptographic random generator rather than the ordinary arithmetic one most scripts use. The values are not predictable from previous results, which is what you want when something of value depends on the outcome.
The range is genuinely uniform
Mapping random bits onto a range with a remainder makes some values slightly more likely than others — a subtle bias most implementations carry. Here values that would cause the bias are discarded and redrawn, so every number in the range is equally likely.
No repeats
With repeats turned off, each number appears once, which is what a raffle or a sample needs. You cannot ask for more numbers than the range contains, and you will be told rather than left waiting.
Nothing is recorded
The numbers are generated in your browser and never transmitted or stored. Nobody, including us, can see or reproduce them.
Random number generator — questions
Is this truly random?
It uses the browser's cryptographic random source, which is not predictable from earlier results. That is as good as software gets without dedicated hardware.
Can I get each number only once?
Yes. Turn repeats off and every number in the set will be distinct.
Is it fair across the whole range?
Yes. Values that would introduce bias are discarded and redrawn, so every number is equally likely.
Are the numbers recorded anywhere?
No. They are generated in your browser and never transmitted.