Twitter is upping the ante for video advertising on its platform, adding autoplay videos and introducing a new standard for viewability.

Starting today, video ads on Twitter will only be chargeable when a video is 100% in-view on a user’s device, and the video has been watched for at least three seconds, according to a blog post introducing the changes. Prior to today’s autoplay announcement a video ad counted as being viewed when it had been clicked.

In contrast, YouTube’s video ads are counted as viewable when 50% of the video has been in-view for at least two seconds, which is the current MRC standard. The company also reports how long a user has watched brand videos. Facebook, which also autoplays videos, counts ads as soon as they are in view for any amount of time.

Twitter is also working with multiple third-party verification vendors, including Nielsen and MOAT, to ensure ads are reaching the right audiences, according to the blog post.

Helping to ensure more videos are viewed by users, Twitter is also introducing autoplay for all native videos, GIFs and Vines on the platform, and presenting videos in a larger, more central place in Tweets. When a user scrolls past a video it will begin to play while muted. Clicking on the video will bring the user into a full-screen viewer, with sound and the video continuing to play.

In autoplay testing, users were 2.5 times more likely to prefer the videos over other options, which have included click-to-play and video preview thumbnails. Users also reported better video recall with autoplay videos, with a boost of 14% over other video formats. Brands using autoplay saw a seven times increase in the number of video completions during testing.

Today’s announced changes are live on desktop and iOS, with Android updates coming soon.