krauseler on GitHub has developed the Muxcard, a fully working computer that is literally the size of a credit card.

I’ve always been interested in extreme space constraints — but this one pushed it to another level. Products like AirTag-style card trackers and similar devices that claim to be “credit-card sized” are usually still far away from actually feeling like one.

The idea of a smartcard with display isn’t new, there have been multiple concepts and prototypes, but I wanted to build a smartcard that is actually the size of a real credit card – including the actual thickness.

The actual prototype is already finished and I will post updates as I’m testing it mostly for durability in daily use and battery life. You can find schematics, layout and some other resources in the repo, but it’s still work in progress.

See more on GitHub.