Facebook is changing the aspect ratios of photos and videos shown in the news feed on mobile devices.

In addition, Facebook is also limiting the amount of text shown in a mobile news feed post.

So if you’re optimizing posts for Facebook’s mobile news feed, these are the new specs you need to pay attention to.

Here’s exactly what’s changing.

Aspect Ratios for Photos and Video

Facebook is reducing the maximum media height for photos and videos from a 2:3 aspect ratio to 4:5 on mobile News Feed.

Media taller than 4:5 will be masked on Facebook’s mobile News Feed, which means users will have to tap on it to see it in full.

Fewer Lines of Text

Less text will be shown in mobile news feed posts, dropping from 7 lines down to 3 lines of primary text.

If the post contains more than 3 lines of text, users will be prompted to click to view additional text.

Both of these changes are coming into effect on August 19th, 2019. This gives marketers at least a few weeks to adjust to using shorter images and less primary text.

Facebook says these changes are “designed to simplify our formats and improve the consistency of our mobile experience.”

The company believes these changes will increase the effectiveness of ads and make it easier to use the same assets across Facebook and Instagram.