Paper is one of those Neal.fun experiences that starts simple and then blows your mind. You have a piece of paper. It’s 0.1mm thick. You click fold. That’s it. But keep clicking and things get ridiculous very quickly.
Every time you fold, the thickness doubles. At first it doesn’t seem like much. A few folds and you’re at a millimetre. A few more and you’re at a centimetre. But exponential growth is sneaky. Before you know it, your paper is taller than a person, then a building, then a mountain. Keep going and it passes aeroplanes, then satellites, then just keeps climbing.
The wild part is how few folds it takes to reach insane heights. Around 42 folds and your paper would theoretically reach the Moon. That’s it. 42 folds. It sounds impossible, and physically it is, but mathematically it checks out. That’s the whole point of the experience. It makes exponential growth feel real in a way that numbers on a page never could.
Each fold comes with a comparison so you can actually picture what’s happening. Seeing your paper go from pocket-sized to taller than Mount Everest in just a handful of clicks is genuinely surprising. Even if you’ve heard the folding paper fact before, watching it play out feels different.
There’s no goal, no score, and no challenge. You just fold and watch. But that simplicity is what makes it work. It’s a quick, clever demonstration of a concept most people underestimate. You’ll probably share it with someone after.
How To Use Paper
There’s nothing to figure out. You open the page, see your paper at 0.1mm, and click the Fold button. Each click doubles the thickness and updates the display with a new comparison.
If you want to go back, there’s an Unfold button that reverses the last fold. You can go up and down as much as you like, watching the numbers jump and drop. It’s satisfying in a weird way.
The whole thing takes maybe a minute or two if you fold all the way to the Moon. There’s no pressure to do anything specific. You can stop whenever you want or keep folding just to see what other comparisons pop up.
Paper is a perfect example of what Neal.fun does best. It takes a simple idea, makes it interactive, and leaves you thinking about it longer than you expected. Quick, clever, and surprisingly memorable.