Recent updates to WhatsApp for iOS has introduced support for Instagram & Facebook video playback.
According to the messaging platform’s latest release notes, YouTube videos have been playable for some time in WhatsApp, which also offers a Picture-in-Picture mode for continuing to watch while switching between chat threads. However, clicking on an Instagram or Facebook video link kicks users out of the app and into the respective hosting platform.
The WhatsApp changelog for version 2.18.51 indicates inline support for Facebook & Instagram videos.
