Maxwell — Javascript Circuit Simulator

Phil Sung <>

[screenshot] Maxwell is a simple web-based tool, suitable for educational purposes, that can simulate circuits containing wires, resistors, and fixed voltage sources.



  1. Build your circuit by dragging circuit elements out of the toolbox (in the top left-hand corner).
  2. Add wires by dragging lines between circuit elements.
  3. Click on elements and type to change source and resistor values.
  4. Click on elements and press Delete to remove them.
  5. Drag the multimeter leads to your circuit to measure voltages.

If you find a bug, please tell me about it.

Supported browsers

Maxwell is implemented in client-side JavaScript and uses the Canvas element. It is known to work on:


Posts tagged "Maxwell" on my blog


You may redistribute and/or modify this program under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the license, or (at your option) any later version.

You can obtain a copy of the source via Git:

git clone

Maxwell contains and makes use of a small Javascript linear algebra library in order to solve the systems of simultaneous equations that characterize a circuit. You may find it useful for other purposes.