Microblogging platform Twitter is officially rolling out ads which will automatically play videos when users are scrolling on their timelines. The new feature is available on desktops and on Twitter for iOS, the company said on its blog. Android users will have to wait longer for autoplay videos (we’re not worried Twitter, take your time).

Note the autoplay feature is only for native videos, GIFs and Vines. Twitter says that while scrolling down the videos will automatically play but will be muted. Clicking on the video will play it in its entirety in the full-screen viewer with sound. If you turn the video to landscape mode, the sound will automatically turn on and the video will expand to fill the screen.

Opt out 

Twitter also added that users have to option revert to the previous click-to-play experience all the time or simply have videos autoplay only when you’re connected to WiFi. In the case of low bandwidth or high data rates, Twitter will opt users out of the feature and will continue videos as click-to-play. Here’s more on how you can choose to opt out of the feature.

No mention of Periscope

It’s worth noting that Twitter hasn’t mentioned whether this will be applied to video streams on Periscope. It’s also been stepping up its efforts for the streaming service and former CEO Dick Costolo also stressed on the same during a recent conference call.  Costolo said that one million people signed up with Periscope within the first 10 days of the application’s launch. And in May, Twitter updated Periscope with the ability to sign up for the service without a Twitter account and new users will now be able to sign up for the app using their phone numbers instead.

For advertisers

Twitter says that with this new feature, it will be charging advertisers for a view. “Starting today we’ll only consider a view on Twitter chargeable when a video is 100% in-view on the user’s device, and has been watched for at least 3 seconds,” Twitter added in a separate blog entry for advertisers. Twitter is also in discussions with ratings agencies Nielsen and Moat for the third-party verification so that advertisers can know that their promoted video content is reaching the right audience.

Note that Facebook debuted autoplay videos on Instagram and Timelines in 2013, but advertisers such as Unilver have pulled back their campaigns on Facebook due to lack of third party verification, as pointed out by this Wall Street Journal report.

Twitter also said that it is putting in a standard of 100% viewability in place i.e. if a video is not 100% in-view, Twitter will not charge advertisers. The Wall Street Journal also notes that The Media Ratings Council and the Interactive Advertising Bureau guidelines state that an online video ad should only be deemed viewable if at least 50% of the ad is visible on a user’s screen for at least two consecutive seconds.