simulator.io alternative: build logic, and a CPU, in the browser
simulator.io describes itself as an online CAD tool for logic circuits, aimed at people building a computer from scratch. You place elements from a palette on a board, wire them, and test the circuit in real time. A team can work on a single synchronized circuit, you can share a snapshot of a board as a unique link or fork someone else's board into your workspace, and registration is free, with anonymous boards too. Its site carries a 2015 copyright by Bastian Born. digiwleea is also free in the browser, with a different focus: a guided path from the transistor to a CPU.
What simulator.io is good at
Working together. Several people editing one synchronized board in real time is rare among free logic simulators, and snapshot links and forks make it easy to hand a circuit to a classmate or build on someone else's. Configurable elements, such as multi-bit binary displays, keep larger designs readable. (digiwleea is an independent project, not affiliated with simulator.io or Bastian Born.)
How digiwleea is different
digiwleea starts one level lower and adds a curriculum. You build NOT and NAND from CMOS transistors, then adders, latches, registers, RAM and control logic, and finally an 8-bit CPU that runs a stored program, plus the assembly language behind it, through a 40+ level course where every part is checked against its truth table, with an AI tutor (Wleea) to help. Finished parts go into your library and become building blocks for the next level, and any circuit can be shared as a link or embedded in a page. There is no real-time co-editing: for building one board together, simulator.io is the better fit.
| simulator.io | digiwleea | |
|---|---|---|
| Runs in | The browser | The browser, phones included |
| Smallest building block | Ready-made logic elements | CMOS transistors |
| Working together | Synchronized team boards, snapshot links, forks | Share or embed a circuit as a link |
| Guided course | No | Yes, 40+ levels up to an 8-bit CPU, with an AI tutor |
| Price | Free | 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.
More comparisons: Logic simulators
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 simulator.io free?
Its site says registration is free, and you can also work on an anonymous board without an account.
Can several people edit a simulator.io circuit at once?
Yes. Its site describes working with a team on a single synchronized circuit; only the board's owner can change the team settings.
What is a good alternative to simulator.io for learning?
digiwleea is a free browser logic simulator with a guided course: you build gates from transistors, then adders, memory and an 8-bit CPU, each checked as you go, with an AI tutor.