101 Circuits is an electronics puzzle game about turning a set of components into a working circuit. Draw wires between terminals and watch the result on the oscilloscope. Each puzzle is solved when every output matches its target signal. Any valid circuit that produces the required signals is accepted.

Explore 101 circuit puzzles

Begin with simple connections and LEDs, then progress to capacitors, filters, transistors, amplifiers, and oscillators. Practice each new idea through several circuits before taking on the next challenge. Smooth a pulse, shape a waveform, or generate a repeating signal.

Learn as you build

The built-in Learn library explains component symbols, connections, and behavior through diagrams, formulas, and practical examples. Puzzle guides help you understand the concepts behind each challenge. Open a component's help or practice circuit directly from a puzzle. Build everything visually with the mouse and keyboard, with no programming required.

Experiment in Sandbox

Use the components you discover to create and save your own circuits. Change supply voltages, resistance, capacitance, and signal settings while watching the results. Pin frequently used values to the bottom control bar and adjust them with knobs or exact numeric entry. Add colored LEDs and see them light as current flows.

Inspect the signals

Choose the Blueprints or Dark theme, zoom into scope traces, and inspect voltage and current measurements. Undo and redo make it easy to try another connection, while saved puzzle progress lets you return to a circuit later.