Like LogicCircuit, but in your browser, from transistors up
LogicCircuit (logiccircuit.org) is free, open-source educational software for designing and simulating digital logic circuits. It is a Windows application, with 64-bit, 32-bit and Arm builds, and it is actively maintained, with version 2.26.09.01 the current release. 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 LogicCircuit is good at
It is a capable and well-kept design tool: circuits can nest without limit and use multi-bit buses, you can debug a running design with its built-in oscilloscope and move around the circuit hierarchy while it runs, and you can export a design as an image or as Verilog. If you are on Windows and want a free, offline logic designer, it is a strong choice. (digiwleea is an independent project, not affiliated with LogicCircuit.)
How digiwleea is different
digiwleea runs in any modern browser, so it works the same on a Mac, a Chromebook, Linux or a phone, with nothing to install. It also starts one layer lower: instead of placing ready-made gates, you build NOT, NAND and the rest from CMOS transistors, and the simulator checks each one against its truth table before you reuse it. A guided 40+ level course then takes you through adders, latches, registers, RAM and control logic to a working 8-bit CPU that you program in assembly, with free theory lessons and an AI tutor (Wleea) alongside. LogicCircuit is the better pick for designing larger logic offline on Windows; digiwleea is the better pick for learning how the whole machine works.
| LogicCircuit | digiwleea | |
|---|---|---|
| Runs on | Windows (64-bit, 32-bit, Arm) | Any modern browser, nothing to install |
| Smallest building block | Pre-built gates and components | CMOS transistors (build the gates too) |
| Signals over time | Built-in oscilloscope | Waveform view over clock cycles |
| HDL export | Verilog | VHDL |
| Guided course to a CPU | No (a design tool) | Yes, 40+ levels |
| Price / license | Free, open source | Free lab and Act I; Premium for the full course |
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 LogicCircuit 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.