What is Logisim.app?

Explore how modern computers work by building them from the ground up. Logisim.app lets you design logic circuits — from simple adders and multiplexers to full ALUs and CPUs — in exactly the same way as the classic Logisim by Carl Burch. Requiring no downloads or setup, it is fully compatible with existing Logisim circuits and instantly available on the web.

How it works

Logisim.app is a 1:1 port that works by running Java on a WebAssembly JVM via CheerpJ. The Java codebase is the same as the original, with a few targeted modifications to allow Logisim to work within the browser’s secure sandbox — including letting users open and save files to disk.