XLA file extension is used by Microsoft Excel software to store program plugins. XLA file contains additional modules and functions that can be used to add features to spreadsheet documents or automate certain processes. XLA file can store VBA macros, which after activation can be run with key shortcuts and/or by using additional buttons accessed through the toolbar.

Users can generate custom XLA files directly in Microsoft Excel. To gain access to addons user must activate function that allows them to be used.