A browser-based electronic circuit simulator with live, animated schematics — build a circuit and watch current, voltage and component behavior in real time.
Why we recommend it
Testing a circuit idea usually means either building it physically or learning a full CAD/simulation suite. CircuitJS1 lets you sketch a schematic and see it behave immediately, which is exactly the feedback loop early-stage hardware design needs.
Strengths
- Free and open source under GPL-2.0. Real-time animated simulation of current and voltage, large library of example circuits, no install required.
Drawbacks
- Interface and visuals are dated — this has been a stable project for a long time and it looks it. Simulation accuracy is good for teaching and prototyping logic, not a substitute for SPICE-level analysis on production designs.
Frequently asked questions
CircuitJS1 is free to use.
Yes, CircuitJS1 is open source under the GPL-2.0 licence.
Interface and visuals are dated — this has been a stable project for a long time and it looks it. Simulation accuracy is good for teaching and prototyping logic, not a substitute for SPICE-level analysis on production designs.
CircuitJS1 is best suited for Industrial Designer, Maker, Product Designer.
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