A simple ACMEv2 client for Windows (for use with Let's Encrypt et al.)


When evolving win-acme, we strive for backwards compatibility and in-place upgrades. A typical upgrade can be deleting everything from the program directory and extracting the new files. This can even be automated by tools like Scoop.

Also win-acme is available as a dotnet tool on

There are some cases when you might want to be a little more careful.

  • When you made changes to the script(s) included with the distributed .zip-file, you will probably want to preserve those. We do accept PR’s for scripts, so if they are the type of changes which others might find useful too, please feel free to submit them.
  • If you made changes to wacs.exe.config, you will probably want to preserve those. If that is the case please be careful to use the newly released file as the baseline and make the necessary changes there, rather than keeping the old file around. This is because the file also contains configuration information for the .NET CLR which has to match the build it’s been generated for.


It’s recommended to review and test all scheduled renewals after an upgrade.


Some versions of win-acme have required or recommended migration steps, which are listed here. “v1.9.5” in this case means that you can or should read this if you’re migrating from a version below 1.9.5 to version 1.9.5 or higher.