How To Compile Less In Visual Studio 2015

In the previous version of Visual Studio (specifically VS 2013), Web Essentials 2013 handled LESS compilation effortlessly. If you forked a project and started editing a LESS file, it would automatically save the compiled .css file in the same folder as the .less file.

In Web Essentials 2015, the LESS compilation feature was removed and no longer works. If you try to use third-party tools like SimpLESS or WinLESS as a replacement, you will run into issues. In my experience, both tools threw an error stating the file was already in use by another process, and Visual Studio kept showing a file-save dialog on every change — and even after saving, the compilation did not work reliably.

Don't worry though — it looks like Mads Kristensen, who removed the LESS compiler from Web Essentials, has since created a dedicated extension to bring the functionality back.

https://visualstudiogallery.msdn.microsoft.com/3b329021-cd7a-4a01-86fc-714c2d05bb6c

You can download it from the link above. The only downside of this extension is that it does not compile LESS files automatically on save. You need to right-click the file and trigger the compilation manually to get it working.