It's not clear how Facebook determines which videos to pre-download or how long the videos stay downloaded to a user's smartphone.
Facebook is testing a new feature that will allow users to watch videos even without an internet connection, TechCrunch reported. Now following it Facebook is testing a new feature called Instant Videos which will download videos over WiFi. Such videos will be marked with a lightning icon. As videos take more time load than web pages, this feature will help publishers gain maximum viewers for their clips.
Previously, Facebook has tried to adapt its service for differing bandwidth and data prices by re-ranking News Feed to prioritize low file-size content while downranking videos if you're on a slow connection, or replaying stories you'd already seen.
If Instant Videos does become a permanent feature on Facebook, videos on the social network would be more accessible to those in regions where mobile data prices can be quite expensive.
Facebook has yet to reveal how it will choose videos for offline caching. That could make the feature a major boon to Facebook's efforts in the developing world. This means that users will be able to watch the videos on the go for free without having to connect to their cellular network.