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Which Video Aspect Ratio Is Best for Facebook Video Ads?

November 13, 2019 • By

Scott Ayres

Does Aspect Ratio Matter on Facebook Video Ads?

If you’re looking for a lower cost per click (CPC) on your Facebook video ads this experiment in the Social Media Lab is for you!

We’re going to find out if the aspect ratio (video size) of videos used in Facebook video ads impact clicks and views

What do we mean by “video aspect ratio”? This refers to the size of the video as seen on devices.

This graphic from Idea Rocket should help visualize the different sizes:

facebook video ads


You notice there are many video size choices an advertiser can choose for Facebook Ads. Is there a preferred video aspect ratio?

Facebook ran 10 A/B tests on the different video aspect ratio sizes for ads and found:

“Seven of the ten tests showed that vertical video ads drove an incremental increase in brand lift, including a three- to nine-point increase in ad recall.”

That’s a 70% swing in favor of vertical videos in Facebook ads.

Even though my assumption was square videos would perform better, due to how they show up on mobile devices, I’m going to lean towards Facebook’s data for my hypothesis.

Hypothesis: Vertical video ads have the lowest CPC on Facebook.

facebook video ads


I’m basing this assumption on the findings Facebook found during its research. But the companies they tested with were big, global brands, so we need to test on a smaller scale.

Testing Video Aspect Ratio on Facebook Ads

The Social Media Lab teamed up with Wave.Video for this experiment. We both ran ads on our Facebook pages to determine if we see a clear winner regarding the video aspect ratio in Facebook ads.

Aspect ratios tested:

  • Square 1:1
  • Vertical 4:5
  • Wide 16:9

Budget: $150 per account, divided between the three video sizes. (Although our ad budget was set to a maximum of $150, the full amount isn’t usually spent due to ad bidding on Facebook and the inventory Facebook has in its system at the time.)



The video below was used (in three aspect ratios) for the Facebook Ads testing for Wave.Video.

This is what the square video ad looked like on Facebook:


This is what the vertical video ad looked like on Facebook:

facebook ads

The video used for Wave.Video had subtitles on all aspect ratios. In addition, all ads had the same text in the update.


Here’s the video used for the Facebook Ads aspect ratio test on Agorapulse’s Facebook page (obviously the size was changed per aspect ratio tested):


On Facebook, the vertical ad looked like this:

facebook video ads

There were no subtitles on the Agorapulse ad. The text in each ad was the same for each aspect ratio.

The Results of Aspect Ratio Test on Facebook Video Ads

When you run a split test on Facebook Ads, you’ll automatically see which ad won based on the objective you are testing.

In this case, we were testing the “Creative,” which was the aspect ratio of the video ads.

Facebook will send an email, such as the one below from a different test, that states which ad won the split test:

facebook ad results

But, for some reason, I never received the email from Facebook on this particular test. This could possibly be due to some sort of glitch on Facebook Ads.

You can also go into Facebook Ads and, after a few clicks, see the winning ad:

facebook ads test

It’s honestly a bit hard to get to inside Facebook Ads Manager. To find the data needed to properly analyze you must:

  • Click on “Manage Ads” inside the Facebook dropdown menu while logged into your personal profile.
  • Select the correct Ads account, if you have multiple ads accounts it becomes even more difficult. Especially if one of the ads accounts is inside Business Manager (which may require 2-3 additional clicks).
  • Find the ad by searching or scrolling through your ads.
  • Dig through the different types of data to view, which can be confusing.

But from there, you’ll see all the detailed data for the test. You can also export the data selected to a spreadsheet for analysis outside of Facebook.

Another great way to see the winning ad is from a free Agorapulse tool called AdsReport. Once connected to the site with your Facebook profile, you can search by ad title, and there is all the info you need:

facebook ads report

I share these only to make you aware of multiple ways to find your data when you test Facebook Ads.

We could look at many data points, but our only focus for this test is CPC.

To properly evaluate this test,  let’s take a look at the combined CPC averages of the Agorapulse and Wave.Video Facebook ads.

  • Square ad: $1.91 CPC
  • Vertical ad: $0.94 CPC
  • Wide ad: $1.79 CPC

The vertical ad had the lowest CPC.

facebook video ads

The CPC of the square ad was 101.19% higher, and the wide ad was 90.43% higher.

Stated another way, the vertical ad was 50.79% lower CPC than the square ad, and 47.49% lower than the wide ad.

Subsequently, the vertical ad had a higher reach, more 3-second views, more ThruPlays, and more consumers that viewed 100% of the video. 



Based on the data from the Social Media Lab testing, combined with data from Wave.Video, we conclude that for Facebook video ads the best aspect ratio to get the lowest CPC is vertical videos.

Our hypothesis was correct, and further supports the findings Facebook made on its A/B testing.

facebook video ads

Vertical video ads saw a 47.49-50.79% lower CPC compared to square and wide video ads on our testing. This amount of savings could make or break a company’s profits, especially as ad budgets go higher and higher.

The Social Media Lab recommends your Facebook video ads be in the 4:5 vertical aspect ratio moving forward to maximize visibility and engagement and save money.