Online circuit simulators compared: which one fits what you want to build
An online circuit simulator lets you draw a circuit in the browser and watch it work, with nothing to install. They split into two families: analog simulators, which compute voltages and currents through resistors, capacitors and transistors, and digital logic simulators, which work with 0s and 1s through gates and flip-flops. A third group simulates microcontroller boards running your code. Here are the well-known ones, side by side. The right one depends on whether you are learning electronics, digital logic or embedded programming.
How to choose
For analog circuits and seeing current flow, start with Falstad's simulator (free) or EveryCircuit; for schematics you will turn into a PCB, EasyEDA; for SPICE-grade simulation online, CircuitLab or Multisim Live. For Arduino, ESP32 or micro:bit projects, Wokwi or Tinkercad Circuits. For digital logic, CircuitVerse and Logisim are the free classroom standards, and digiwleea is a free browser course that builds gates from transistors and goes all the way to a CPU. (digiwleea is an independent project, not affiliated with any of the tools listed.)
Where digiwleea fits
digiwleea is a digital logic simulator: it works at the switch level, so every wire is 0, 1 or floating, and you start from NMOS and PMOS transistors rather than ready-made gates. You build NOT and NAND, then adders, latches, registers, RAM and 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). It does not simulate analog circuits or microcontrollers, so for those the tools above are the better choice.
The simulators side by side
| Simulator | Kind | Runs in | Price (October 2026) |
|---|---|---|---|
| Falstad Circuit Simulator | Analog and digital, animated current | Browser (also offline versions) | Free |
| CircuitLab | Mixed-mode analog and digital | Browser | Memberships from $24 a year |
| Multisim Live | SPICE, analog and digital | Browser (desktop Multisim on Windows) | Free to try; desktop by license |
| EveryCircuit | Analog and digital, animated | Browser, Android, iOS | Free up to 5 components; $5 a month or $15 once |
| EasyEDA | Schematic and PCB, simple simulation | Browser or desktop client | Free |
| Tinkercad Circuits | Breadboard circuits, Arduino and micro:bit | Browser | Free |
| Wokwi | Microcontroller boards and parts | Browser, VS Code | Free for personal use |
| CircuitVerse | Digital logic, classroom features | Browser | Free, open source |
| Logisim | Digital logic | Java desktop; classic Logisim at logisim.app | Free, open source |
| digiwleea | Digital logic from transistors, with a course to a CPU | Browser, phones included | Free lab and Act I; Premium course |
Each name links to a fuller, side-by-side comparison with digiwleea. Looking for PartSim? It shut down in 2023. More digital logic simulators are compared in our pages on Logicly, Digital and DigitalJS, and logic gate games in the games roundup.
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
What is the best free online circuit simulator?
For analog circuits, Falstad's Circuit Simulator is free in the browser and shows current flowing. For digital logic, CircuitVerse and digiwleea are free in the browser. For Arduino projects, Tinkercad Circuits is free and Wokwi is free for personal use.
What is the difference between an analog and a digital circuit simulator?
An analog simulator computes voltages and currents through every component, like SPICE. A digital logic simulator treats signals as 0 and 1 (and sometimes floating), which is simpler and faster and is what you need to learn gates, flip-flops and CPUs.
Can I simulate a digital circuit online for free?
Yes. CircuitVerse and digiwleea are free digital logic simulators in the browser, and Falstad's simulator also includes logic gates alongside its analog parts.
Which online simulator is best for learning how a CPU works?
One that lets you build up from gates: digiwleea's free browser course goes from transistors to an 8-bit CPU that runs a stored program, and CircuitVerse and Logisim let you build processors from gates on your own.