What is a WLL file? A WLL file is an add-in used by Microsoft Word, a word processing application. It contains a software component that adds new features to the program, similar to a plugin . Examples of add-ins include calculators, writing assistants, emoji keyboards, and text-to-speech converters.

More Information The WLL file type was introduced in 1996 with the release of Microsoft Word 97. It is saved in the same format as the Dynamic Link Library ( .DLL ) file type but is renamed with the .wll file extension to indicate its association with Word. When Microsoft released Office 2016, it replaced WLL files with Node.js Word add-ins. These add-ins typically consist of an .XML , .HTML , .CSS , and .JS file. To access them from the Office Add-ins store in Word 365, select the "Insert" tab, then click "Get Add-ins." While Microsoft developed some add-ins, third-party software developers developed most of them. Most WLL files were created using Microsoft Visual Basic for Applications. Since being replaced, WLL files are uncommon. However, Word 2016 and later versions still support them. You can manually place a WLL file in the \​Microsoft\​Word\​Startup\​ folder and the add-in will load when Word starts up.