digiwleea: a free Falstad alternative
Paul Falstad's Circuit Simulator Applet is a much-loved tool for analog and digital circuits, showing current as animated moving dots. If that is what brought you here, digiwleea is a free, in-browser alternative with a different angle: you build a computer from the transistor up.
What Falstad is good at
Falstad is wonderful for analog intuition and for seeing voltage and current flow in real time across a huge range of circuits.
How digiwleea is different
digiwleea is narrower and more pedagogical: it is specifically about building digital logic from switch-level CMOS up to a CPU, as a structured course rather than a freeform analog playground. You get a level-by-level path, a reusable parts library that grows as you learn, achievements, and an AI tutor, all aimed at one clear destination: understanding how a computer is built.
| Falstad | digiwleea | |
|---|---|---|
| Focus | Analog + digital, freeform | Digital logic, transistor to CPU |
| Learning path | Open exploration | Structured 30+ level course |
| Reusable parts library | Subcircuits | Yes, every level saves a part |
| AI tutor | No | Yes (Wleea) |
| Price / install | Free, in-browser | Free, in-browser |
No sign-up is needed to start: open the lab and place your first transistor, or read the free theory course. The account (and the AI tutor) are optional.
See for yourself: build a logic gate from transistors in the simulator, then follow the path from sand to an 8-bit CPU.
Open the digiwleea lab →Frequently asked
Is digiwleea a good Falstad alternative?
Yes, if you want to understand digital logic from the ground up. digiwleea is a free, in-browser simulator and 30+ level course where you build every gate from CMOS transistors and work up to a real 8-bit CPU, with an AI tutor to help.
Is digiwleea free?
The sandbox lab and the first act of the course are free and need no sign-up. An optional account adds the AI tutor and cross-device sync; the full course and tutor are a one-time unlock plus an optional subscription.
Do I need to install anything?
No. digiwleea runs entirely in your browser, on desktop or mobile, and works offline once loaded.