Uploading a video as your Facebook cover video is as simple as uploading a new photo. Though you can upload it only on your Business Facebook page
Note: Facebook video cover feature is a new Beta feature on Facebook, and sometimes, you might not be able to upload your video successfully, as it simply might not load.
So if you are not able to upload your video as Facebook cover, we would suggest you to wait a bit and try again later.
Currently it is not possible to upload the video directly on Facebook page as a cover as it was possible before. Now you can upload only images directly on the Facebook cover.
In order to add or change your Page's cover video:
Go to your Facebook page.
Upload your video on Facebook page
Once your video is uploaded on your Facebook page, you need to click on Edit in the bottom right of your cover photo or video
Select Choose From Videos to use a video you've already uploaded to your Page. Keep in mind your cover video should be at least 820 x 312 pixels and between 20 and 90 seconds.
Note: For FB cover you need to download the video in Widescreen ratio from your Promo account. And for your text to look the best on your cover, make sure to place it in the center of the video. If the text is placed directly in the center of the footage, it will be perfectly visible on your cover page.
Select the video from your existing videos.
Note: Recently Facebook introduced a new interface, where the video can show up with borders.
After the video has been added, if you want your video on FB cover to replay automatically in a loop, you can Enable or Disable this feature. Then click on Next.
Click the arrows to scroll through up to 10 thumbnail options for your cover video. The thumbnail image may be used when someone hovers over your Page's name to get more context about your Page.
Once you choose the thumbnail you can click on Save Changes, and your video will be posted on FB cover
Done :) Your FB cover should be successfully uploaded on your Business Page :)
And if later you decide to remove your cover video, the video won't be automatically deleted and will still be available in your Page's video library.
Please keep the following in mind when choosing a cover video:
Make sure that your cover video follows the Facebook Pages Terms. Cover videos can't be deceptive, misleading or infringe on anyone's copyright.
Your Facebook Page's cover video should be at least 820 x 312 pixels.
Your Page's cover video should be between 20 and 90 seconds.