Industrial automation software has traditionally been expensive — Studio 5000 and TIA Portal cost tens of thousands per year per seat. But a growing ecosystem of free and open-source tools covers most development needs. Here's the complete list for 2026.
Free PLC Programming IDEs
Plaxio — Best Overall
Free. Windows + macOS. AI-powered.
Plaxio is the most modern free PLC IDE available. It includes Ladder Diagram, FBD, and SFC editors with AI code generation, a built-in IEC 61131-3 runtime for simulation, and vendor-neutral export to Rockwell L5X, Siemens SimaticML, Schneider XEF, and PLCopen XML.
- AI generates PLC code from plain English descriptions
- Built-in simulation (no separate simulator needed)
- Git-compatible project files
- Exports to any major PLC brand
- Auto-documentation generation
- 100% offline operation
CODESYS Development System
Free IDE, runtime licensed per device.
CODESYS is the most widely deployed IEC 61131-3 platform. The Development System IDE is free to download. Devices that run the CODESYS runtime (Wago, Beckhoff, FESTO, ifm) require a per-device runtime license from the device manufacturer.
- Supports all 5 IEC 61131-3 languages including IL and CFC
- SoftMotion for coordinated motion control
- Built-in visualization (WebVisu)
- Cannot target Rockwell or Siemens hardware
- No AI features
OpenPLC Editor
Free, open-source.
OpenPLC is an open-source IEC 61131-3 PLC runtime that runs on Raspberry Pi, Arduino, and other microcontrollers. Good for learning and hobbyist projects, but lacks the polish and AI features of commercial tools.
- Runs on Raspberry Pi, Arduino, ESP32
- Supports LD, FBD, SFC, ST, IL
- Good for education and prototyping
- Not suitable for industrial production environments
LDMicro
Free, Windows only.
LDMicro is a lightweight Ladder Logic compiler for AVR and PIC microcontrollers. Very minimal — good for simple microcontroller projects, not for real PLC work.
Free SCADA / HMI Software
Inductive Automation Ignition (Trial)
Ignition is one of the best SCADA platforms available. It's not free in production but offers an unlimited trial that only adds a watermark after 2 hours of runtime. Used widely for development, training, and proof-of-concept.
ScadaBR
Open-source SCADA based on Mango Automation. Java-based, runs on any OS. Good community support. Not as polished as commercial options but fully functional for many applications.
Node-RED
Not a traditional SCADA, but widely used for industrial dashboards and automation flows. Runs on any Node.js platform including Raspberry Pi. Excellent for connecting to MQTT, OPC-UA, and Modbus devices. Free and open-source.
Free Simulation Tools
Plaxio (built-in simulator)
Plaxio includes a full IEC 61131-3 runtime simulator. No separate tool needed. Toggle inputs, monitor tags, step through scan cycles — all within the IDE.
Factory I/O (free tier)
Factory I/O is a 3D industrial simulation environment. Connect virtual PLCs, sensors, and actuators to real or virtual PLC programs. Free tier includes limited scenes. Good for learning and demonstration.
Visual Components Free
Free version of the Visual Components 3D simulation platform. Limited features but useful for basic virtual commissioning and layout visualization.
Free Network and Protocol Tools
Wireshark
Free network analyzer. Essential for debugging industrial Ethernet protocols (EtherNet/IP, PROFINET, Modbus TCP). Runs on Windows, macOS, Linux.
MQTT Explorer
Free MQTT client and broker explorer. Essential for IIoT projects and any system using MQTT for machine data collection.
OPC UA client (UA Expert)
UaExpert is a free OPC UA client from Unified Automation. Use it to browse OPC UA servers, read/write tags, and test OPC UA configurations without writing any code.
Free Learning Resources
- What is Ladder Logic? — Free guide to getting started
- How to program a PLC — Step-by-step beginner tutorial
- IEC 61131-3 Tutorial — The international PLC standard explained
- PLC simulation guide — Test without hardware
The Recommended Free Stack
For most engineers learning or developing PLC programs without a large budget:
- Plaxio — PLC programming, AI generation, simulation, vendor export
- Node-RED — Data collection, dashboards, IIoT connectivity
- Ignition trial — SCADA development and testing
- Wireshark — Network diagnostics
- UA Expert — OPC UA diagnostics
This combination covers 90% of industrial automation development needs at zero cost.
Start with Plaxio
The most capable free PLC IDE available. AI code generation, simulation, and vendor-neutral export — all free.
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