This is a widely publicized hack that enables you to download videos from Facebook Messenger. Once you have downloaded the video, you can choose to Unsave it from your Facebook account by clicking on the three-dots icon next to the Add to Collection button, and clicking Unsave.You can find the video in the Downloads folder in your computer. Click on the video, and it will automatically download to your computer.Under All, you will see the video you saved. In the new tab, you will see the My Collections screen.This will open a new tab in your browser. On the left side of the video, you will find a three-dot icon (More).Then go to the conversation with the video you want to download.
This approach works for downloading Facebook Messenger videos using your Windows Computer. Download Facebook Messenger Videos on Windows