Circuit simulators for Linux: logic, SPICE and HDL, compared
Linux has some of the best free circuit simulators, but they do different jobs. Digital logic simulators let you wire gates and flip-flops and see 0s and 1s: Logisim-evolution (packages for Debian, Ubuntu and Fedora with Java included) and Helmut Neemann's Digital (a Java application). SPICE simulators compute voltages and currents in analog circuits: ngspice (command-line, also the engine inside KiCad) and Sandia's Xyce (built for very large, parallel simulations), with Qucs-S as a schematic front end for both. KTechlab, a KDE application, pairs circuit simulation with PIC microcontroller programming. For hardware description languages, GHDL simulates VHDL. Pick by what you are learning: digital logic, analog circuits, microcontrollers or HDL.
How to choose
For a digital logic course, Logisim-evolution or Digital. For analog circuits with a schematic editor, Qucs-S on top of ngspice, or Xyce for very large simulations. For PIC projects, KTechlab. For VHDL, GHDL; our Icarus Verilog vs Verilator vs GHDL page compares the HDL simulators. (digiwleea is an independent project, not affiliated with any of these tools.)
A browser option, on Linux and everywhere else
digiwleea runs in any modern browser on Linux, with nothing to install and no Java. It is a digital logic lab that starts below the gates: you wire NMOS and PMOS transistors into NOT and NAND, then build adders, latches, registers, RAM and an 8-bit CPU that runs a stored program, through a 40+ level course where every part is checked against its truth table, with an AI tutor (Wleea). It has no analog or microcontroller simulation; for those, use the tools above.
The Linux simulators side by side
| Simulates | How it installs on Linux | |
|---|---|---|
| Logisim-evolution | Digital logic, with a chronogram | .deb or .rpm with Java included, or a .jar |
| Digital | Digital logic | Java application (needs a Java runtime) |
| Qucs-S | Analog, through ngspice, Xyce or others | Packages and a wiki install guide |
| ngspice | Analog SPICE, plus event-driven digital | Builds on Linux; command line |
| Xyce | Analog SPICE, very large and parallel | Executables and source from Sandia |
| KTechlab | Circuits and PIC microcontrollers | KDE app (Discover or package manager) |
| GHDL | VHDL | Command line |
| digiwleea | Digital logic from transistors to a CPU | Nothing: runs in the 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.
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 circuit simulator for Linux?
For digital logic, Logisim-evolution or Digital; for analog SPICE simulation, ngspice or Xyce, with Qucs-S as a graphical front end; for PIC microcontrollers, KTechlab. All are free and open source.
Is there a logic simulator for Linux that needs no install?
Yes. digiwleea runs in the browser on Linux, with no Java or packages to install.
Does Logisim run on Linux?
Logisim-evolution has .deb and .rpm packages that include Java, and an all-platform .jar that needs Java 21 or newer.