How GoPickaro Picks Winners

When people trust you with a giveaway, "it's random" is not enough. Here is exactly how each GoPickaro tool decides a result.

The random source: Web Crypto

All three tools use crypto.getRandomValues(), part of the Web Crypto API built into every modern browser. It draws on the operating system's secure randomness, the same source browsers use to create encryption keys. Unlike ordinary pseudo-random functions, its output cannot be predicted from earlier results.

When a tool needs a whole number, such as "which of these 37 names", GoPickaro uses rejection sampling. A random 32-bit value that would make some numbers slightly more likely than others is discarded and a new one is drawn. This removes the small bias that a simple remainder calculation would introduce.

Spin Wheel

The Spin Wheel has two rings: participants on the outer ring and prizes on the inner ring.

1. Every line you type becomes one slice, and all slices on a ring are the same size.
2. When you press spin, the tool picks a random number of full turns and a random final angle for each ring, separately. At this moment the outcome is already fixed.
3. The rings then animate in opposite directions and slow down to that angle. Whatever slice stops under each pointer is the winner and the prize.

Because the final angle is uniform across the full circle and all slices are equal, every participant and every prize has exactly the same chance.

Prize quantities and repeat winners

On the wheel, writing T-shirt x3 creates one T-shirt slice with a quantity of three. Each time a winner of that prize is confirmed, the quantity goes down by one, and the slice disappears when it reaches zero. The prize is not more likely because of its quantity, it simply stays on the wheel longer. Every prize that has been confirmed leaves the wheel or loses one from its quantity.

With Remove winner from list after winning turned on, a person who wins also leaves the wheel and cannot win again. When comments are imported from YouTube with Unique names only checked, each commenter gets one slice, however many comments they left.

In Instant Draw quantities work differently: T-shirt x3 adds three T-shirts to the prize list before the draw.

Instant Draw

Instant Draw is built for long lists where spinning one by one would take too long.

• The participant list and the prize list are each shuffled with the Fisher-Yates algorithm, using the secure random source above. Every possible order is equally likely.
• Winners are then taken from the top of the shuffled list, so no one can be drawn twice in the same draw.
• With No duplicate winners checked, a name that appears more than once in your list counts only once.
• With Each prize once only checked, each prize goes to one winner. Unchecked, each winner receives a prize picked at random from the list, so the same prize can appear more than once.

Dice Roller

In the Dice Roller, the value of every die is generated the instant you press Roll, with an equal chance for each face from 1 to the number of sides. The fast-changing numbers you see are only an animation that lands on the value already chosen. Nothing about the animation, the sound or the timing can change the result.

What we do not do

• No hidden weighting, and no setting that favors any entry.
• No server-side draw. The result is not sent to us to be decided or approved.
• No uploading of your lists. Names and prizes are processed in your browser.

The code runs in plain sight: any visitor can open the page source in their browser and read how the draw works.

Tips for a giveaway your audience will trust

1. Publish the rules first. Entry method, deadline, number of winners and prizes, before anyone enters.
2. Clean the list. Decide whether people may enter more than once, and remove duplicates if not.
3. Show the list before the draw. Let entrants see their names are in.
4. Draw in public. Spin live on stream, or record your screen from the moment you paste the list.
5. Use 1× Spin for important prizes, so you can confirm each winner on camera.
6. Keep the results. Print or save the winners list at the end of the draw.
7. Check your platform's rules. Instagram, YouTube, TikTok and Twitch each have their own policies for promotions and giveaways.

Questions

Can the host or GoPickaro influence the result?

No. The result is generated on the device running the draw when the button is pressed, and there is no option to weight or pre-select an entry.

Does a name that appears twice have a better chance?

On the Spin Wheel, yes: each line is a slice. In Instant Draw, not when No duplicate winners is checked. Remove duplicates if every person should have one chance.

Something looks wrong with a result. What should I do?

Please contact us with the tool name, your browser and, if possible, a screenshot or recording. We look into every report.

For step-by-step help with a real draw, read how to run a fair giveaway or browse all our guides.