Best Free PLC Simulators in 2026
Every free PLC simulator and SoftPLC currently available — broken into logic simulators (run your code) and process simulators (test it against virtual machinery). Direct download links, what each is actually free for, and what they pair best with.
Logic vs process simulators
Logic simulator = a SoftPLC that runs your ladder/ST code on a PC, with simulated I/O bits you can flip manually. CODESYS Control Win, OpenPLC, PLCSIM.
Process simulator = a virtual machine (3D scene, tank model, conveyor) that connects to a SoftPLC over Modbus or OPC UA, so your code drives realistic process behaviour. Factory I/O is the paid leader; MachineSimulator and DIY Python stacks are free alternatives.
At-a-glance comparison
| # | Simulator | Type | Free for |
|---|---|---|---|
| #1 | CODESYS Control Win V3 CODESYS Group | logic | 30-day trial then licence |
| #2 | OpenPLC + Editor OpenPLC Project | logic | Forever — GPL |
| #3 | PLC Fiddle PLC Fiddle | logic | Forever — free tier |
| #4 | Siemens PLCSIM (with TIA Portal trial) Siemens | logic | During TIA Portal 21-day trial |
| #5 | Studio 5000 Logix Emulate (with trial) Rockwell Automation | logic | During 90-day Studio 5000 trial |
| #6 | CCW Micro800 Simulator Rockwell Automation | logic | Forever — free with CCW |
| #7 | GX Works3 Simulator Mitsubishi Electric | logic | During 30-day trial |
| #8 | Factory I/O free alternative — MachineSimulator MachineSimulator | process | Forever — limited free version |
| #9 | Open-source process simulator: pyModSlave + custom GUI DIY | process | Free |
CODESYS Control Win V3
A fully functional SoftPLC running on your Windows PC. Lets you test IEC 61131-3 code without hardware. Pair with the free CODESYS Development System.
OpenPLC + Editor
Open-source ladder logic and structured text simulator. Runs your IEC 61131-3 code with simulated I/O for free. Same code deploys to Arduino or Raspberry Pi.
PLC Fiddle
Browser-based ladder logic editor with built-in simulator. No install. Great for sharing code snippets and learning. Free tier sufficient for hobby and learning.
Siemens PLCSIM (with TIA Portal trial)
Siemens S7-1500 / S7-1200 simulator integrated with TIA Portal. Full simulation of Siemens hardware including PROFINET. Available during the TIA Portal trial.
Studio 5000 Logix Emulate (with trial)
Allen-Bradley ControlLogix simulator. Runs your Studio 5000 code without a real CPU. Excellent for learning and testing complex routines.
CCW Micro800 Simulator
Built-in simulator for Allen-Bradley Micro800 series within Connected Components Workbench. CCW itself is free; the simulator is included.
GX Works3 Simulator
Built-in simulator within GX Works3 for Mitsubishi MELSEC iQ-R / iQ-F / Q / F series. Run ladder, ST, FBD without real hardware.
Factory I/O free alternative — MachineSimulator
Free 3D process simulator alternative to Factory I/O. Connect to OpenPLC, CODESYS or any Modbus TCP master. Smaller scene library than Factory I/O but enough for learning.
Open-source process simulator: pyModSlave + custom GUI
Python Modbus slave simulating tank levels, conveyor positions, motor states. Pair with OpenPLC for a full free stack. Tutorials abound on YouTube and GitHub.