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One animated circuit is worth a thousand equations and diagrams. Animations of voltages, currents, and charges are displayed right on top of the schematic, providing great insight into circuit operation. The real-time circuit simulation engine is custom-built for speed and interactivity. Easy one-click simulation, from simple resistors and logic gates to complex transistor-level oscillators and mixed-signal designs. While the simulation is running, you can flip switches, adjust potentiometers, tune LED current limiting resistors, ramp up input voltages, etc. The circuit will immediately respond to your changes, in real time. Mini-waveforms on top of schematic wires look different for digital and analog signals. Constant analog voltages are shown as numbers, digital wires are color-coded. Any pair of time-domain signals may be plotted in the XY mode. The oscilloscope scale and grid ticks are auto-updated to convenient values as the data changes.

CircuitSim is a full SPICE circuit simulator with a 3,000+ component library and a modern schematic editor. No install, free to get started. Built for students, educators, and professionals. It runs in a browser tab and needs no admin rights, so it works on Chromebooks and locked-down school laptops. Run seven kinds of analysis: interactive, interactive operating point, transient, AC sweep, DC operating point, DC sweep, and parameter sweep. Results plot on oscilloscope-style charts, with probes you can drop anywhere in the circuit. Define custom parts from SPICE model text or import KiCad symbols. CircuitSim also imports Multisim Live designs ahead of that product's retirement on September 15, 2026. It is the only browser tool that opens .csim, .ms14, and .msjs files, and it rebuilds the schematic with wiring, placement, net labels, probes, and simulation settings intact. Classroom licensing adds seat assignment, anonymous student seats, and private student work.