Like LTspice, but in your browser and built for digital logic
LTspice, from Analog Devices, is a free SPICE simulator with schematic capture and a waveform viewer, built to simulate analog circuits accurately, with models for the company's parts and a library of ready-to-run demo circuits. It is a desktop download for Windows (x64 and Arm) and macOS. 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 LTspice is good at
It is fast, free and unlimited, with transient, AC and noise analysis, support for third-party models, video tutorials from the basics up, and a community forum on EngineerZone. If you need real voltages, currents and timing in an analog or power circuit, it is a strong choice. (digiwleea is an independent project, not affiliated with Analog Devices.)
How digiwleea is different
digiwleea is not a SPICE simulator: it treats transistors as switches, which is the level you need to understand digital logic and computers rather than analog behavior. It runs in any browser with nothing to install, so it also answers "LTspice online" for logic, and its course takes you from CMOS gates through adders, latches, registers and RAM to an 8-bit CPU that you program in assembly, with an AI tutor (Wleea). LTspice is the better pick for analog and power circuits; digiwleea is the better pick for learning digital logic and computer architecture.
| LTspice | digiwleea | |
|---|---|---|
| Simulation | SPICE: analog voltages and currents over time | Switch-level digital logic |
| Runs on | Windows and macOS (desktop download) | Any modern browser, nothing to install |
| Price | Free | Free lab and Act I; Premium for the full course |
| Guided course to a CPU | No (tutorials and demo circuits) | Yes, 40+ levels |
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 LTspice alternative?
Yes, if you want to understand digital logic from the ground up. digiwleea is a free, in-browser simulator with a guided 40+ 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 expanded AI tutoring are included in the monthly or annual Premium subscription.
Do I need to install anything?
No. digiwleea runs entirely in your browser, on desktop or mobile, and works offline once loaded.