About
Why randzen exists
RandZen does exactly one job: draws cryptographically secure random numbers, integers and dice rolls within a range you set. That is the whole of the site. No account, no newsletter, and no wall between you and the number you came for.
Why we built this
Search for everyday-utility tools and you will mostly find pages that bury a single calculation under cookie walls, newsletter modals and three paragraphs of filler. We built RandZen as the opposite: one focused tool that draws cryptographically secure random numbers, integers and dice rolls within a range you set, and nothing between you and the answer. Keeping it that narrow is what makes it fast, and what makes it honest about how the result is produced.
How it works
No server is involved in the arithmetic. It takes values from the browser's secure random source and maps them onto your range without modulo bias, so every outcome stays equally likely even when the range does not divide evenly into the generator's output. We state the method openly because a tool that cannot explain its own answer is not much use to anyone trying to trust it.
Your data stays here
The ranges and counts you set never leave your browser. There is no backend that receives them, no database that stores them, and no advertiser that sees them — so you can load the page, disconnect from the internet, and the tool keeps working.
Who it is for
- anyone who needs the answer in a single step.
- people on a slow or metered connection.
- readers who dislike registering for a calculator.
Who pays for this
Advertising pays for the running of RandZen; nothing here is subscription-based. No advertiser is given the values you enter, and an advert appearing beside a tool is never a recommendation of it.
Tell us what you think
Spotted a mistake or missing a feature? The contact page takes it. The suggestions that get acted on usually come from people who actually use the random number and dice generator.