For placements where video ads are eligible for auto-play, some conditions need to be met. These conditions are meant to enhance the experience that people have on Facebook's family of apps and services (including Instagram, Messenger and Audience Network). Some reasons why video ads may not auto-play include:

• People turn off auto-play within their settings.
• Auto-play is set to Wi-Fi-only in their settings, but Wi-Fi is off on the device.
• The Wi-Fi or cellular connection on the device is weak.
• The battery is low on the device.
• The ad's minimum pixel percentage for auto-play isn't in view.
• The device or browser doesn't support auto-play. Alternatively, the person using the device or browser turns off auto-play in settings.

Learn more

• Video ad playing specifications by placement

* Nguồn: Facebook