How to Use the Free Online Circuit Simulator

This guide walks you through everything you need to start simulating electronic circuits in your browser. No electronics experience required.

The Interface Overview

When the simulator loads, you'll see three main areas:

• Canvas (centre) — where you draw and view your circuit
• Menu bar (top) — File, Edit, Draw, Circuits, Scope, Options, Help
• Right panel — simulation controls and component information

A default LRC circuit loads automatically so you can see the simulator in action immediately. Green areas indicate positive voltage, red indicates negative, and yellow dots show current direction and magnitude.

Running Your First Simulation

The simulator starts running automatically. To control playback:

• Press Space or click the Run/Stop button to pause and resume
• Use the speed slider on the right panel to run faster or slower
• Press R to reset the simulation to its initial state

Adding Components

Right-click anywhere on the empty canvas to open the component menu. You can also use the Draw menu in the menu bar.

To place a component:

1. Right-click the canvas and choose a component (e.g., "Add Resistor")
2. Click and drag on the canvas to place it — the drag direction sets orientation
3. Release the mouse to place the component

To place a wire, right-click and select "Add Wire" then click and drag between two points.

Editing Component Values

Double-click any component to open its properties panel. You can change:

• Resistance (for resistors) in ohms, kilohms, or megaohms
• Capacitance (for capacitors) in farads, microfarads, or picofarads
• Frequency and amplitude for voltage sources
• All other component-specific parameters

Changes take effect immediately while the simulation is running. This lets you tune component values and watch the circuit respond in real time.

Loading Example Circuits

The simulator includes 360+ pre-built example circuits. To access them:

1. Click Circuits in the menu bar
2. Browse the categories (Basics, Filters, Diodes, Op-Amps, etc.)
3. Click any circuit name to load it instantly

You can also visit the Circuits Library to browse and launch circuits with one click.

Using the Oscilloscope

To probe a node and view its waveform:

1. Click Scope in the menu bar, then select "New Scope"
2. Click on any wire or component in the circuit to add it to the scope
3. The oscilloscope panel appears at the bottom showing voltage over time

You can add multiple probes to compare waveforms. Right-click the oscilloscope to change scale and display options.

Saving Your Circuit

Your circuit is not automatically saved. To preserve your work:

• Export as URL: File → Export as URL → Copy the generated link. Paste it in your browser's address bar any time to reload your circuit.
• Export as Text: File → Export as Text → Copy the text and save it in a text file for later import.
• Bookmark the URL: After loading a circuit, the URL in your browser updates. Bookmarking it saves your circuit permanently.

Keyboard Shortcuts

• Space — Run/Pause simulation
• R — Reset simulation
• Ctrl+Z — Undo
• Delete — Delete selected component
• Ctrl+A — Select all
• Ctrl+C / Ctrl+V — Copy / Paste
• Scroll wheel — Zoom in/out
• Click + Drag on empty space — Pan the canvas

Next Steps

Now that you know the basics, try these guides to go deeper:

• Ohm's Law — Visualised in a Simulator
• 555 Timer Circuit Guide
• Op-Amp Circuits for Beginners