Open Facebook and find the video you want to download
Click or tap the three-dot menu on the post
Select Copy link
Open a trusted Facebook video downloader website or app
Paste the copied link into the downloader
Click Download or Start
Choose the video quality if prompted
Save the video to your device
If the video is your own, open Facebook and go to your post or Page
Click or tap the three-dot menu on the video
Select Download video if available
If download is not available, ask the owner for permission or a copy of the video