Circuit Lab is an experimental, open-source workspace for drawing circuits and running Arduino Uno code in your browser.
Draw and edit
Use the component palette to place boards and parts. Move components on the canvas, use Wire to connect pins, and switch to Code Editor to edit a sketch. The palette includes visual components whose simulation models are incomplete.
Compile on your device
Verify or Simulate compiles one .ino sketch for one Arduino Uno on your device and runs the resulting AVR firmware. The first compilation downloads about 68 MB of compiler files, with loading progress and cancellation. Cached files are reused when browser storage is available. Extra libraries, multi-file compilation and physical board uploads are unavailable.
Save your work
Save downloads a JSON project containing your components, wires and sketch files. Open restores that project. File also offers Save to Local Storage and Load from Local Storage for this browser.
Experimental circuit models
The component engine is unfinished: breadboard connectivity is inaccurate; resistor current, capacitor charging and electrical transients are not calculated; buttons, sensors, analog inputs, motors and displays may have missing or inaccurate behavior. Background tabs may slow simulation. Verify electrical behavior using real hardware or a validated simulator. Read all limitations and source information.
Based on the MIT-licensed SimuIDE Web editor, with Hamnus browser-side compilation.