About

Small tools, built to be honest

A wheel of fortune, a coin, some dice and a deck of cards. Nothing else, on purpose.

Why only randomisers?

There is no shortage of websites that will flip a coin for you. This one exists because most of them make a claim they cannot back up, and because the same six tools can be built without a single line of server code.

Every tool here runs entirely in your browser. There is no backend, no database and no account, which means nothing to sign up for, nothing to go wrong, and no data about you to leak. It also means the whole site is a handful of files that could not be simpler.

The randomness claim, taken seriously

A page whose entire purpose is producing a random number has an obligation to actually produce a random number. Most simple web tools use JavaScript's Math.random(), which is fast but weak: it draws from 32 bits of state and its output can be predicted if you know enough of it.

These tools use crypto.getRandomValues() instead — the Web Crypto API generator, seeded by your operating system from hardware entropy and considered suitable for cryptographic use. Where a result is chosen from a range, it is rejection-sampled rather than reduced modulo the range size, so no outcome is even slightly more likely than another.

That claim is easy to make and cheap to check, so we built the randomness check: it runs a chi-square test on tens of thousands of draws from the same generator these tools use, in your browser, and reports whether the distribution holds up. It is the fastest way to judge whether a site like this is telling the truth, which is why it is one of the tools rather than a claim on a page about us.

Being useful, not just thin

A page that is nothing but a button is not much use to anyone, and search engines have noticed that about small utility sites generally. So each tool carries an explanation of how it works, what it is genuinely good for, and where it stops being the right tool — including the parts that are less interesting to read but more useful to know.

Where there is a genuine statistical point to make, we make it rather than leaving it out. A coin flip has no memory. A 53% result after a thousand throws is not a signal. These are the things people most often get wrong about randomness, and a page that generates randomness is a reasonable place to say so.

Advertising

The site is free and kept free by advertising through Google AdSense. Ads are chosen by Google, not by us, and we have no control over which appear. We do not ask anyone to click them.

Corrections and problems

If a tool gives a wrong answer, a page is confusing, or something here is simply untrue, please say so at contact@grunners.vip. Reports about bugs are genuinely welcome, and the randomness claim in particular is one we would rather you tested than took on trust.