IEC 61131-3 engineering · source-checked July 2026

CODESYS Download: Free IDE, Simulator & Setup (2026)

CODESYS Development System is a free IEC 61131-3 engineering environment for Windows. As of 25 July 2026, CODESYS lists V3.5 SP22 Patch 3 (3.5.22.30). The IDE is free, but production runtimes, device packages and professional add-ons have separate licences and support boundaries.

Testing methodology Editorial policyEvidence checked 25 July 2026

CODESYS proof-of-fit workbench checking IDE release, device package, compiler, libraries and runtime target — A reproducible CODESYS test records the whole toolchain, not only the project file.

Current V3 release

3.5.22.30

IDE price

Free download

Native engineering OS

Windows

Target runtime

Device-specific

Official download path

One-time store registration is required. Use CODESYS Installer to manage versions and packages that match the target device.

Download from the CODESYS Store

Which path should you choose?

Option	Choose it when	Boundary to verify
CODESYS Development System	You need a free IEC 61131-3 IDE, offline project engineering, simulation or a vendor device built on the CODESYS platform.	The free IDE is not a perpetual production runtime licence and does not guarantee that one vendor’s project will deploy unchanged to another.
CODESYS Control runtime	You need a SoftPLC or supported runtime on Windows, Linux, Raspberry Pi or another listed target.	Runtime editions, demo behavior, licences and hardware support differ. Verify the exact Store product and device requirements.
Professional Developer Edition	Your team needs supported Git, static analysis, profiling, test automation or other professional engineering add-ons.	These are optional licensed tools. A PDE subscription is separate from the free Development System.

IEC 61131-3 programming languages applied to one machine control problem in a CODESYS learning workflow — Language familiarity helps, but the device package and runtime still determine what deploys.

CODESYS portability boundary between standard PLC logic, vendor libraries, fieldbus configuration and target runtime — IEC syntax is only one layer of portability; libraries and hardware configuration remain device-specific.

Tested installation path

1Create a CODESYS Store account and download CODESYS Installer or the official Development System package.
2Install the V3.5 release required by the target controller; do not automatically upgrade a production project before checking vendor compatibility.
3Use CODESYS Installer to add the target manufacturer’s device description and required libraries.
4Open or create a project for the exact device. If learning only, use simulation or the bundled Control Win SL demo rather than guessing at a production target.
5Compile the application, inspect warnings, exercise I/O states and timers, and record the CODESYS/compiler/library versions.
6Before deployment, verify runtime licence, firmware, fieldbus packages, retain behavior, watchdog settings and recovery procedure on the real controller.

CODESYS IEC 61131-3 data model connecting variables, function blocks, tasks and visualisation — A clear data model makes simulation, review and later device integration easier.

Support and capability boundaries

CODESYS lists V3.5 SP22 Patch 3 (3.5.22.30) on 23 July 2026; vendor-branded controllers may certify a different release.
The Development System download is free, while production SoftPLC runtimes and optional add-ons can require separate licences.
The base setup includes a demo of CODESYS Control Win SL; demo behavior is not the same as an activated production runtime.
Instruction List is marked obsolete and is no longer maintained, although it can be enabled where required.
Device packages, libraries and runtime implementations create portability boundaries even when projects use IEC 61131-3 languages.

Proof-of-fit checklist

Controller vendor and certified CODESYS service pack
Device package and compiler version
Runtime edition, licence and demo restrictions
Library versions and namespace conflicts
Fieldbus and safety package compatibility
Retain, online-change and watchdog behavior
Backup, source control and tested restore procedure

CODESYS program organization unit model with programs, functions, function blocks and shared libraries — Reusable POUs are valuable only when their dependencies and target assumptions are documented.

CODESYS task execution model showing cyclic and event tasks, watchdogs and runtime scheduling checks — Timing and scheduling must be validated on the target runtime, not inferred from desktop simulation.

Related training product

Use browser practice for the lesson; use CODESYS for the device

PLC Simulation Software offers guided ladder and Structured Text exercises without a Windows install. It is useful for concept practice before you configure the real CODESYS device, libraries and runtime.

Practise CODESYS-style PLC logic

Ownership disclosure: PLC Programming IO and PLC Simulation Software share ownership. Browser practice does not replace CODESYS, its device packages or a licensed target runtime.

Official sources used

CODESYS Development System

CODESYS describes the free Development System, IEC 61131-3 editors and bundled Control Win SL demo.

CODESYS V3 release history

Official release dates, patch versions and documented restrictions.

CODESYS Store download

Official download, current price and package/version history.

Professional Developer Edition

Optional Git, static-analysis, profiling and test-tool scope plus its separate subscription boundary.

Continue researching

CODESYS tutorial CODESYS vs TwinCAT Structured Text guide