Digital Logic
LOGIC LABSimulate gates, flip-flops, counters, registers, RAM, and a complete ALU — over 60 components with live truth tables and probeable signals. Follow templates all the way to an 8-bit CPU that runs your assembly.
Real-time engine · no install · free to start
The circuit simulator that runs live in your browser.
Build digital logic, relay, electricity, and analog circuits on one bench. Drag a component, wire it, and watch every signal flow in real time — from your first AND gate to an 8-bit CPU.
No account needed · works on any laptop · 7 languages
60+logic components
66narrated lessons
25relay Blueprints
7languages
Four simulators, one bench
Everything you’d wire on a real workbench
Each lab shares the same bench, save format, and real-time engine — switch domains without switching tools.
Relay
Electromechanical logic on a real DC solver — coils pull, contacts click, and ladder logic latches. Follow 25 guided Blueprints from one relay to a binary counter.
Electricity
Batteries, bulbs, meters, and rheostats make Ohm’s and Kirchhoff’s laws visible, measurable, and safe to explore.
Analog
Build op-amp, filter, diode, and transistor circuits with DigiSim’s own Rust circuit engine compiled to WebAssembly.
Who it’s for
Built for the classroom and the workbench
Students and self-learners
Learn by probing, not by reading
Pause a lesson, flip a switch, and inspect the live circuit. Follow the journey from one clicking relay to a working computer.
Educators
Embed a live lab in any course page
Put an interactive simulator in an LMS, presentation, or website. Classroom adds a teacher dashboard, invitations, and join codes.
Hobbyists and engineers
Sketch an idea before you solder it
Test a latch, debounce a switch, or size a resistor network in the browser before touching a breadboard.
SimCast · Professor Mode
Lessons that don't just play. They teach.
Press play and a finished circuit comes alive. The lesson highlights one component, narrates the idea, then pans the camera to the next. Pause anywhere — every signal is still probeable, because it's still a simulator.
- ✓66 narrated lessons, 21 free — in 7 languages
- ✓From first gate to CPU, organized into guided SimCast Sets
- ✓Interactive at every frame — never just a video
Pricing
One toolkit. Choose how you pay.
Start free, subscribe monthly or annually, choose the Founder one-time offer while available, or manage Classroom seats.
Free
$0
no card required
Start free- Logic & electricity sandbox
- Up to 30 components
- 21 free SimCast lessons
- Community templates
Pro
$58 /yr
≈ $4.83/mo · save 19%
Get Pro- Every component, every lab
- All four simulators available now
- Cloud save & full SimCast library
- AI circuit assistant
Founder
$99 once
one payment · no recurring fee
Claim Founder offer- Everything in Pro
- All four simulators
- No recurring fee
- Future simulator updates included
Classroom
$4 /seat · yr
billed annually · from 20 seats
Get seats- Everything in Pro
- Teacher dashboard
- Invitations & join code
- Stripe seat management
Already own a previous one-time tier? Your existing entitlement is grandfathered, with no new subscription required. Eligible academic accounts receive an automatic discount at checkout. Secure payment by Stripe.
FAQ
Common questions
Is DigiSim free to use?
Yes. Start with useful free sandboxes, lessons, and templates. No account or installation is needed.
What circuits can I simulate?
Digital logic, relay and ladder logic, DC electricity, and analog op-amp, filter, diode, and transistor circuits.
Do I need to install anything?
No. DigiSim runs in a browser on laptops, Chromebooks, and tablets.
Can I use it for teaching?
Yes. Embed live circuits, assign SimCast lessons, and manage class seats with Classroom.
Are all four simulator labs available?
Yes. Digital Logic, Relay, Electricity, and Analog are available now.
Is my work saved?
Free circuits save locally. Pro adds cloud save, sharing, export, and cross-device access.
Start at the click. End at a computer.
No account. No install. The first relay is one tap away.