Software guide
How to install CODESYS for free (step by step)
A free PLC development system for Windows. It is optional: every course Try it also works in the browser.
Last checked 18 Oct 2026.
What it is for
Time
Works on
Official page
Before you download
The official store lists the CODESYS Development System at 0,00 EUR plus VAT and says no licence is needed. The setup includes a demo version of the CODESYS Control Win SL soft PLC. Demo runtimes can stop after a while and need a restart: read CODESYS's own help for the exact limit.
Checked on the official site on 18 Oct 2026.
What you need
- Windows 10 or Windows 11 (64-bit). The store page does not list macOS or Linux.
- Recommended: 8 GB RAM, a 2.5 GHz processor and 12 GB of free disk space
- A CODESYS Store account may be asked for at download
Install it
1.Open the CODESYS Development System page on store.codesys.com and choose the download.
You should see: A setup file starts to download. Sign in to the store if it asks.
2.Run the downloaded setup file and accept the licence terms.
You should see: The installer lists the components it will install.
3.Keep the default components and press Install. Allow the Windows prompt.
You should see: A progress bar runs and ends on a finished screen.
4.Open CODESYS from the Start menu.
You should see: The CODESYS window opens with an empty start page.
This tool does not run on macOS. The steps below use the browser option.
1.CODESYS does not run on macOS. Use LADX Mini instead: it works in your browser and covers the same practice.
You should see: LADX Mini opens in a new tab.
2.Open edwartens.com/internships/tools/ladx-mini and follow the browser guide for LADX Mini.
You should see: You are on the browser tool's page, ready to start.
This tool does not run on Linux. The steps below use the browser option.
1.CODESYS does not run on Linux. Use LADX Mini instead: it works in your browser and covers the same practice.
You should see: LADX Mini opens in a new tab.
2.Open edwartens.com/internships/tools/ladx-mini and follow the browser guide for LADX Mini.
You should see: You are on the browser tool's page, ready to start.
Check that it works
1.Choose File, New Project, then Standard project. Pick the soft PLC device if the wizard offers one, and the language ST.
You should see: A project tree opens with a program called PLC_PRG.
2.Type a short line such as x := TRUE; in PLC_PRG, then build the project.
You should see: The messages window ends with no errors.
If something goes wrong
- The installer asks for an administrator password.
- Run it from an account that can install software, or ask the owner of the computer.
- I am on a Mac or Linux computer.
- CODESYS does not run there. Use LADX Mini in your browser for the same practice. A Windows virtual machine is an advanced option.
- The build shows errors.
- Read the first message and double-click it to jump to the line. Fix that one first.
- The soft PLC stopped by itself.
- Demo runtimes can stop after a while. Start the runtime again and log in to the project again.
- The download needs an account.
- Create a free store account on the official CODESYS site only. Never use a download from another website.
If you cannot or do not want to install
LADX Mini runs ladder logic in your browser with nothing to install.
Open the browser guideUninstall
- Open Windows Settings, then Apps.
- Find CODESYS in the list and choose Uninstall. Repeat for the soft PLC components it installed.
Which internships use it
- PLC Programming internship, in week 7.
The first 4 weeks of every internship are free. This is training, not employment, and there is no stipend. All software guides.