Is Roulety completely free to use?

Yes, Roulety is 100% free. There are no premium plans, hidden fees, or feature locks. All functionality is available to everyone without creating an account.

Is the spinner wheel truly random?

Yes. Roulety uses the Web Crypto API (window.crypto.getRandomValues), which provides cryptographically secure random numbers. This is the same technology used in security and encryption applications, making the results genuinely unpredictable and fair.

Do I need to create an account or sign up?

No. Roulety works instantly in your browser with no registration required. Your wheel entries and settings are stored locally on your device.

Does Roulety work on mobile devices?

Yes. Roulety is fully responsive and works on smartphones, tablets, and desktops. The layout automatically adjusts to fit your screen size.

Can I use Roulety for giveaways or contests?

Absolutely. Many content creators and event organizers use Roulety for giveaways, raffles, and prize drawings. The cryptographic randomness ensures fair and unbiased selection.

Where is my data stored?

All your data — wheel entries, settings, and spin history — is stored locally in your browser using localStorage. Nothing is sent to or stored on our servers.

Technology · 6 min read

What Is Cryptographic Randomness and Why Does It Matter for Spinner Wheels?

Learn how cryptographic random number generation works and why it produces fairer results than standard pseudo-random methods.

When you spin a wheel online, you expect the result to be random and fair. But not all randomness is created equal. Most websites use Math.random(), a built-in JavaScript function that generates pseudo-random numbers. While these numbers appear random on the surface, they are actually produced by a deterministic algorithm. If someone knows the internal state of the generator, they can predict every future output.

Roulety takes a fundamentally different approach. Instead of Math.random(), it uses the Web Crypto API — specifically, window.crypto.getRandomValues(). This function is designed for cryptographic applications where unpredictability is not just desirable but essential, such as generating encryption keys, secure tokens, and digital signatures.

How the Web Crypto API Works

The Web Crypto API draws its randomness from the operating system's entropy pool. Entropy is a measure of genuine unpredictability, and it comes from physical sources that are inherently chaotic: the precise timing of keystrokes, mouse movements, disk I/O operations, network packet arrival times, and even thermal noise in hardware components.

The operating system continuously collects these tiny, unpredictable events and mixes them together using cryptographic algorithms (like ChaCha20 or AES in counter mode) to produce a stream of random bytes. When a web application calls crypto.getRandomValues(), the browser requests random data from this pool, producing numbers that are computationally indistinguishable from true randomness.

Why This Matters for a Spinner Wheel

For a casual spinner wheel, you might wonder if this level of randomness is overkill. Here is why it matters:

Fairness and Trust — When you use a spinner wheel for a giveaway, classroom activity, or team decision, the participants need to trust that the result is fair. With cryptographic randomness, no one — not even the person who set up the wheel — can predict or influence the outcome.

No Patterns — Pseudo-random generators can exhibit subtle patterns over large numbers of spins. For example, Math.random() in some JavaScript engines produces numbers with slight biases in certain bit positions. Cryptographic generators are specifically designed and tested to avoid any such patterns.

Resistance to Manipulation — In competitive contexts like giveaways with real prizes, the integrity of the random selection is critical. Cryptographic randomness ensures that the result cannot be reverse-engineered or tampered with.

The Technical Details

When Roulety needs to determine where the wheel lands, it generates a random 32-bit unsigned integer using crypto.getRandomValues(new Uint32Array(1)). This produces a number between 0 and 4,294,967,295, which is then mapped uniformly to a position on the wheel. The mapping is done carefully to avoid modulo bias — a common pitfall where certain outcomes become slightly more probable than others when the range of the random number generator is not evenly divisible by the number of wheel segments.

Conclusion

True randomness might seem like a small detail, but it is the foundation of a fair and trustworthy spinner wheel. By using the Web Crypto API, Roulety provides the strongest guarantee of fairness available in a web browser — the same level of randomness that protects your online banking, encrypted messages, and secure connections. Every spin is as fair as technology allows it to be.