⚡ FREE · NO DOWNLOAD · NO ACCOUNT · GUIDED SIMULATIONS

The Easiest Way to Learn Circuits —
With Guided Simulations

Build real electronic circuits in your browser. Start from zero and follow our step-by-step guides — each one explains what's happening and why, with a live interactive simulation right there on the page.

🔰 Try Your First Circuit in 2 Minutes Open Simulator

Not sure where to start? Begin with Electronics for Beginners →

360+ Example Circuits
100% Free Forever
0 Downloads Required
50+ Component Types
14 Languages
// new to electronics?

Not Sure Where to Start?

Begin with the basics. Each guide includes a live circuit you can modify and experiment with. No experience needed.

🔰
Start Here
Electronics for complete beginners — voltage, current, resistance explained simply
⚡
Ohm's Law
The most important equation in electronics — simulated live
🔗
Series vs Parallel
How to connect components and how it changes circuit behaviour
✨
AI Circuit Explainer
Describe any circuit — get an instant plain-English explanation
✨
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AI Circuit Explainer — Understand any circuit in seconds
Describe a circuit, get a plain-English explanation. Free & unlimited.
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FreeCircuitSim — Interactive Simulator
Full Screen ↗ Examples Help
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// capabilities

Everything You Need to Simulate Circuits

A professional-grade simulator that runs entirely in your browser. No installation, no account, no cost.

⚡
Real-Time SPICE Simulation
Watch current flow animated in real time. Voltage, current, and power visualised with colour-coded indicators as your circuit runs.
🔧
50+ Component Types
Resistors, capacitors, inductors, diodes, transistors (NPN/PNP/MOSFET/JFET), op-amps, logic gates, 555 timers, transformers and more.
📱
Works on Any Device
Fully responsive design. Use it on your laptop, tablet, or desktop. No app store, no download, no account needed — ever.
📊
Built-in Oscilloscope
Probe any node and display voltage and current waveforms with the integrated oscilloscope panel. Export data for external analysis.
💾
Save & Share Circuits
Export circuits as URLs to share with others or save your work. Import from text files. Load 360+ pre-built example circuits instantly.
🌍
14 Languages
Available in English, German, French, Spanish, Portuguese, Italian, Japanese, Chinese, Korean, Russian, Polish, Czech, Danish and Norwegian.
🔬
AVR8 Microcontroller
Simulate Arduino-compatible AVR8 microcontrollers directly in the browser. Write code and see it control your circuit in real time.
🔓
100% Open Source
Built on CircuitJS1, licensed under GPL v2. The simulation engine is maintained by the open source community and continuously improved.
// example circuits

360+ Ready-to-Run Circuits

Click any circuit below to load it instantly in the simulator. No setup required.

Basics
Ohm's Law
Visualise voltage, current and resistance
A/C Circuits
LRC Circuit
Inductance, resistance and capacitance
Diodes
Full-Wave Rectifier
AC to DC conversion with diode bridge
555 Timer
Square Wave Generator
Classic 555 astable oscillator circuit
Op-Amps
Op-Amp Basics
Operational amplifier fundamentals
Digital Logic
D Flip-Flop
Edge-triggered data flip-flop
CMOS
CMOS Inverter
Complementary MOSFET logic gate
Power
Boost Converter
DC-DC step-up power converter
View All 360+ Circuits →
// comparison

Best Free Multisim Alternative

Multisim Live is shutting down in September 2026. FreeCircuitSim is the best free replacement — no installation needed.

Feature FreeCircuitSim Multisim Live LTspice Falstad.com
Completely Free ✓ ✗ Paid ✓ ✓
No Download Required ✓ ✗ Shutting down ✗ Download ✓
No Account Needed ✓ ✗ Login required ✓ ✓
Works on Mobile ✓ ✗ Limited ✗ Desktop only ✗ Poor mobile
Real-Time Animation ✓ ✓ ✗ ✓
360+ Example Circuits ✓ ✗ ✗ ✓
AVR Microcontroller Support ✓ ✗ ✗ ✗
Available After Sep 2026 ✓ ✗ Shutting down ✓ ✓
// getting started

Start Simulating in 30 Seconds

01
Open the Simulator
Click "Launch Simulator Now" above. The circuit simulator loads instantly in your browser — no download or account needed.
02
Load an Example or Draw
Choose from 360+ built-in examples via the Circuits menu, or start drawing your own circuit by right-clicking the canvas.
03
Run the Simulation
Click the Play button. Watch current flow in real time, probe any wire for voltage readings, and observe waveforms on the oscilloscope.
04
Adjust and Explore
Double-click any component to change its values. See how the circuit responds instantly. Export your circuit as a URL to share or save.
// learning resources

Electronics Guides & Tutorials

Step-by-step guides for beginners and advanced students. Learn circuits by simulating them.

Beginner
How to Use the Circuit Simulator
Complete walkthrough of all simulator features, tools, and controls for new users.
Beginner
Ohm's Law — Simulated
Understand voltage, current and resistance by watching them interact in a live simulation.
Intermediate
555 Timer Circuit Guide
Build and simulate astable, monostable and bistable 555 timer configurations.
Intermediate
Op-Amp Circuit Basics
Inverting, non-inverting, summing and differential amplifier configurations explained.
Beginner
Logic Gates Explained
AND, OR, NOT, NAND, NOR, XOR gates simulated and explained visually.
Info
Multisim Alternative Guide
Switching from Multisim Live? Everything you need to know about moving to FreeCircuitSim.
// faq

Frequently Asked Questions

Is this circuit simulator completely free?
Yes, completely free. No subscription, no trial period, no premium tier, no hidden costs. The simulator is based on the open-source CircuitJS1 project and will remain free forever.
Do I need to create an account or sign up?
No account, no email, no signup of any kind. Just open the page and start simulating. Your circuits are stored in the URL so you can save them by bookmarking the page.
Is this a good replacement for Multisim Live?
Yes. Multisim Live is shutting down in September 2026. FreeCircuitSim offers real-time animated simulation, a large component library, and 360+ example circuits — all for free in your browser with no account needed.
What components does the simulator support?
The simulator supports over 50 component types including resistors, capacitors, inductors, diodes, Zener diodes, NPN/PNP transistors, MOSFETs, JFETs, op-amps, logic gates (AND, OR, NOT, NAND, NOR, XOR), 555 timers, transformers, voltage sources, current sources, and more.
Does it work on mobile and tablets?
Yes. The simulator works on desktop, laptop, tablet, and mobile browsers. Chrome is recommended for the best experience. Touch input is supported for drawing and interacting with circuits.
How do I save my circuit?
Use File → Export as URL to generate a shareable link containing your complete circuit. Bookmark this URL to save your work. You can also export as a text file using File → Export as Text.
Is this the same as Falstad's circuit simulator?
Yes — FreeCircuitSim is built on CircuitJS1, the same open-source engine that powers Falstad's simulator. We host our own compiled version with additional SEO content, tutorials, and a cleaner interface built around it.
Can I use this for university coursework?
Absolutely. This simulator is widely used in electronics education. It supports the circuits covered in most introductory electronics and electrical engineering courses, from basic Ohm's Law to advanced op-amp configurations, digital logic, and power converters.
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// about

Built for Learners,
Not Just Engineers

FreeCircuitSim is a free educational tool for students, hobbyists, and complete beginners who want to understand how electronic circuits work. Every guide is written in plain English, with real-world examples and a live simulation you can modify and experiment with right on the page.

The simulation engine is built on CircuitJS1, the open-source project by Paul Falstad and Iain Sharp. Free to use, free forever, no account required.

Start Learning Free → Browse All Guides
24
Guide Pages
7
Guided Sims
360+
Circuit Examples
$0
Forever