Falstad
Falstad is the Falstad Circuit Simulator, an interactive tool for creating and simulating electrical circuits. Developed by Paul Falstad, it enables real-time visualization of how circuits behave, making it a popular resource in education and self-study. The original simulator began as a Java applet and ran in browsers that supported Java. In response to changes in browser security and plugin support, a JavaScript port called CircuitJS was released, allowing use directly in modern web browsers without plugins. The online version is widely accessible at Falstad’s website, and the code has been published and ported by the community.
The simulator models circuits using a real-time time-domain solver. Users place symbols for components such as
Falstad is commonly used in classrooms, tutorials, and online demonstrations to illustrate fundamental concepts in electronics,