Across Facebook's family of apps and services, a video impression may be counted that does not include a video play. It's important to understand the difference between an impression and a play.

For a video ad to trigger auto-play or animation through click-to-play, a minimum percentage of pixels must be in view for Facebook and Instagram. The minimum percentage of pixels depends on the placement.

For Audience Network, a video ad may begin playing at any time, but Facebook has standards for attributing watch time to any ad impression.

Standards by platform and placement

Facebook

• Facebook feed: 50% or more of the video ad pixels must be in view for the ad to play.
• Instant Articles: 100% of the video ad pixels must be in view for the ad to play.
• Facebook in-stream videos: 50% or more of the video ad pixels must be in view for the ad to play. If the video content is auto-play, the video must be the central feature of the page.
• Facebook-suggested videos: 50% of the video ad pixels must be in view for the ad to play. The video nearest to the centre of the screen will play if >50% of two videos are in the viewport.
• Marketplace: 50% or more of the video ad pixels must be in view for the ad to play.

Instagram

• Instagram feed: 25% of video ad pixels must be in view for the ad to play.
• Instagram Stories: 100% of video ad pixels must be in view for the ad to play.

Audience Network

• Audience Network in-stream: Video ads may begin to play at any point the browser loads the page, but 50% of video ad pixels must be in view to record watch time (% of video watched, avg. video watch time) with ads reporting.
• Audience Network native, banner and interstitial: 50% or more of the video ad pixels must be in view for the ad to play.
• Audience Network rewarded video: 100% of the video ad pixels must be in view for the ad to play.

* Nguồn: Facebook