Build digital logic, relay, electricity and analog circuits on one bench. Drag a component, wire it up, and watch every signal flow in real time — from your first AND gate to an 8-bit CPU running assembly you wrote.
Each lab shares the same bench, the same save format, and the same real-time engine — switch domains without switching tools.
THE CORE LAB Simulate logic gates, flip-flops, counters, registers, RAM and a full ALU — 60+ components with live truth tables and probeable signals. Follow the templates all the way to an 8-bit CPU that runs assembly you write yourself.
Electromechanical logic on a real DC solver — coils pull, contacts click, ladder logic latches. 25 guided Blueprints, from one relay to a binary counter.
Open the Relay Lab → NEW
Batteries, bulbs, meters and rheostats. Ohm’s and Kirchhoff’s laws you can see, measure and break — the physics course before the logic course.
Open the Electricity Lab → IN DEVELOPMENT
Op-amps, filters and transistors on an ngspice-accurate SPICE engine compiled to WebAssembly. Pro subscribers get it the day it ships.
Coming to Pro & FounderEvery circuit in the docs, blog and lesson catalog is a live simulation — pause a lesson, flip a switch, and watch the truth table respond. Follow the 18-part Code journey from one clicking relay to a working computer.
Drop any circuit into your LMS, slides or blog as a real interactive simulator — not a screenshot. Classroom plans add a teacher dashboard, bulk seats and SSO, and academic emails get an automatic discount.
Test a latch, debounce a switch, or size a resistor network in the browser before touching a breadboard. Cloud save keeps your bench, and an AI assistant helps wire and debug circuits with you.
Press play and a finished circuit comes alive: the lesson highlights a component, narrates the idea, then pans to the next. Pause anywhere — every signal stays probeable, because it is still a simulator underneath.
Subscribe once and get logic, relay & electricity today — analog unlocks automatically the moment it is ready.
free forever
Start free≈ $4.83/mo · save 20%
Get Propay once · own it forever
Claim Founder dealbilled annually · from 20 seats
Get seatsAlready own a one-time tier? You’re grandfathered in — every feature you paid for stays yours, with no new subscription required. Academic emails get an automatic discount at checkout. Secure payment by Stripe.
Yes — the logic and electricity sandbox is free forever, with up to 30 components, 21 narrated lessons and community templates. No account or install is needed to start.
Logic gates, flip-flops, adders, registers, RAM and full CPUs; relay and ladder logic; DC circuits with batteries, meters and bulbs — and analog op-amps and filters when the Analog Lab ships.
No. DigiSim runs entirely in the browser on any laptop, Chromebook or tablet — the simulation engine is WebAssembly-fast and works offline once loaded.
That’s what it is built for. Embed live circuits in your LMS or slides, assign SimCast lessons, and manage a class with per-seat Classroom pricing, a teacher dashboard and SSO.
Pro and Founder plans include every new simulator automatically, at no extra charge. You are never billed for a domain that has not shipped.
Free circuits save locally in your browser; Pro adds cloud save so your bench follows you across devices — plus export for sharing and version history.
No install, no signup to try. Open the bench and start wiring.
