Circuit Simulator
A visual electronics lab in your browser. Place components on a grid — voltage sources, resistors, capacitors, inductors, diodes, LEDs, switches — and wire them together; the simulator solves the circuit with modified nodal analysis many times per second and animates the result. Moving dots show the direction and magnitude of current in every branch, wires are shaded by node voltage, and a built-in oscilloscope traces any probed voltage over time so you can watch a capacitor charge, an RC filter smooth a square wave or an LED light up as you close a switch. Presets load classic circuits — voltage divider, RC charging, LC oscillator, full-wave rectifier — ready to run and modify.
Runs 100% in your browser — simulations are computed locally on your device.
Read the full guide to this tool
Notes
- The solver builds the modified nodal analysis (MNA) matrix every step: Kirchhoff’s current law at each node plus extra equations for the voltage sources, then a direct linear solve.
- Capacitors and inductors are integrated with the backward-Euler companion model, which stays stable even with large time steps; diodes and LEDs iterate a linearized Shockley model (Newton’s method) until the operating point converges.
- Components are ideal: wires have zero resistance, sources have no internal resistance and nothing burns out — a short circuit across a battery simply reports a very large current instead of smoke.
- Runs 100% in your browser — simulations are computed locally on your device.
Related tools
Airfoil Designer & Analyzer
Shape a NACA airfoil, see its pressure distribution and plot lift and drag polars, XFOIL-style, in the browser.
Bottle Rocket Simulator
Fill a soda-bottle water rocket, pump it up and launch it: find the water level, pressure and fins that fly highest.
Bridge Builder & Truss Simulator
Design a truss bridge, send a truck across and watch every member strain, buckle or snap under load.
Earthquake Shake Table Simulator
Shake a multi-story building with an earthquake and watch it sway, crack or survive, with base isolation and dampers.
Gear Generator
Design involute spur gears, racks and planetary sets, watch them mesh and export SVG or DXF for laser cutting.
Nuclear Reactor Simulator
Run a pressurized-water reactor: pull control rods, manage xenon and temperature — or SCRAM before it overheats.