Check whether the video has a built-in download option
Open the Facebook video post
Click the three-dot menu on the post or video
Select Download video if available
If no download option appears, copy the video link
Use a trusted third-party Facebook video downloader
Paste the copied link into the downloader
Choose the video quality if prompted
Click the download button
Save the file to your device
On mobile, use the browser version of Facebook if the app does not show download options
Make sure you have permission to download and use the video
Avoid suspicious sites, pop-ups, and fake download buttons