Geeks like myself are bothered by the fact that we cannot (actually, we can) use an animated background in Microsoft Teams.

The Problem

GIF Images cannot be Added in the GUI.

Microsoft Teams does not allow the upload of GIF images as virtual backgrounds.

When trying to change the image format into another one, the upload fails with the error message "Couldn't add background".

The Solution

Add GIF Images Directly.

There is a trick that allows adding GIFs and it works!

Step-by-Step Guide

1. Choose an animated GIF and change the file extension into .png. If the image is called animated.gif, rename it into animated.png.
2. Duplicate the file and add a _thumb (abbreviation for thumbnail) to the name. In the example, the second file is called animated_thumb.png.
3. Copy both files directly into the background image folder of Microsoft Teams (See Windows or Mac below).
4. Restart Microsoft Teams.
5. Join a meeting and choose your new, animated background!

Windows

Default Windows location: C:\Users\YOUR-USERNAME\AppData\Roaming\Microsoft\Teams\Backgrounds\Uploads (you can access this folder by pressing Win + R, typing %appdata% into the field and clicking Ok).

Mac

Default macOS location: ~/Library/Application Support/Microsoft/Teams/Backgrounds/Uploads (the ~ stands for the home directory).

Conclusion

That's it.