The Impact of iOS 14 Update on Facebook Ads

Reading Time: 6 minutes

In January of 2021, Apple began to enforce App Tracking Transparency (ATT), and since then, there’s been a lot of buzz around poor-performing Facebook ads. But what are the actual changes since the iOS 14 update and what’s the impact on the results so far? 

Let’s go through all you need to know…

With the latest iOS 14 update, Apple introduced the so-called App Tracking Transparency (ATT) which gives people more control over their data and how it’s used by Facebook. 

“Privacy is a fundamental human right and at the core of everything we do. That’s why, with iOS 14, we’re giving you more control over the data you share and more transparency into how it’s used.”

Basically, to remain in Apple’s App Store, all apps will be required to ask users if they want to opt into third-party tracking. You will now see pop-ups like this when on your iPhone:

app tracking transparency message on apple devices

Changes on Facebook after the iOS 14 update



Unlimited conversion events and up to 40 custom events

Only 8 events can be tracked – including standard events and custom conversions for measurement and optimization

Pixels – unlimited

1 pixel per domain + domain verification

28-day click, 1-day view attribution window (default)

7-day click, 1-day view attribution window (default)

ℹ️ Conversion event – Facebook will show your ad to people in your target audience who are most likely to complete that conversion event. (View Content, Add To Cart, Purchase, Lead, etc.) 

ℹ️ Attribution window – the time during which your conversion event can be credited to your ads and used to inform your optimization.  

Changes in conversion events

With the new update, you are now limited to having 8 conversion events per domain.

You’ll also need to rank these 8 events in order of importance because Facebook will only track your highest prioritized event.

If you’re an e-commerce business, and “purchase” is ranked as your highest priority event. If a user decides to opt-out and completes multiple events on your website (i.e. “add to cart” and “purchase”) only 1 event will be reported – in this case, the purchase event since it’s the higher prioritized one. 

On the flip side, if the user decides to opt-in and share their data, you’ll be able to see data for all 8 events.

Changes in attribution windows

As a result of the impact created by Apple’s policy requirements, Facebook also made some updates to attribution windows. Many of you probably noticed that the default window changed from a 28-day click/1-day-view to a 7-day click.

While the 7-day click attribution window is now the default for both reporting and optimization, you are also able to choose the following ones:

  • 1-day click or view
  • 7-day click or view
  • 1-day click

This change won’t affect your reporting if you’re advertising a low-ticket product or if most of your conversions occur within a 7-day period.

On the other hand, if you’re selling something that requires a more considered purchase, such as luxury products, or if you have longer purchase cycles you will most likely see a decrease in the number of conversions.

Changes in reporting

As we previously mentioned, if a user decides to opt-out out of tracking, Facebook will only receive the data of the highest prioritized event. However, in some cases, there may be a delay of up to three days on data to show in your reporting.

In that case, Facebook may use statistical modeling for some attribution windows to account for a loss of iOS 14 data. Facebook says it will use in-product annotations to show when modeling is used. 

facebook ads statistical modeling in ads manager after iOS 14 update

Also, keep in mind that the impact on the reporting will be different depending on the percentage of users coming from an iOS device.

For example, take a look at the two charts below where we analyzed two different businesses based on the device their users are coming from.

In the first chart, 93.9% of the traffic are iPhone users. Which means that up to 93.9% percent of this business’ website custom audiences and reporting may be impacted.

On the other hand, the second graph shows us that the majority of the traffic is coming from Android users, which means that this business is going to see a much smaller difference in reporting.

facebook ads mobile traffic data after iOS 14 update

facebook ads android vs iphone traffic performance after iOS 14 update
Desktop vs. Mobile - iOS14

What you need to do (if you still haven’t)


The first and most important step you want to do after the iOS 14 update is to verify your domains with Facebook. 

If you still haven’t done so, below you can find the steps that will help you complete the entire process.

Step 1: Go to Business Settings → Brand Safety → Domains

Once you are on the Domains page, you’ll see a list of domains associated with your account. 

Below each domain name, you’ll see whether that domain is “Verified” or “Not Verified”.

Step 2: Click on a domain that you’d like to verify and choose between the following verification options: 

  1. Meta-tag Verification
  2. HTML File Upload
  3. DNS Verification

You can choose the option that you’re most familiar with, but it’s usually best to have a web developer do this for you.

Aggregated Event Measurement – PRIORITIZE YOUR 8 EVENTS

Up next comes event prioritization. You’re going to want to pick the top 8 events that are most important to you. If you’re an e-commerce business, your top priority event should be purchase.

  1. Go to Events Manager
  2. Click the pixel you want to use.
  3. Then click the Aggregated Event Measurement tab, which is below the overview graph.
  4. Click Configure Web Events.
  5. Read through the introduction screens and click Next.
  6. Find the domain you want to configure events for.
  7. Click Verify Domain. If you’ve already verified your domain, you can skip to the next step.
  8. Hit Edit Events.
  9. Select your pixel or custom conversion under Pixel / Custom Conversion.
  10. Choose the event you want to configure under Event Name.
  11. Drag and drop your events from highest priority at the top, to lowest priority at the bottom.
  12. Click Apply.
  13. Review your event configuration changes. If your changes are correct, check the box and click Confirm.

Keep in mind that because only the highest priority event will be sent whenever a customer takes multiple actions during a conversion window, all other events may report numbers that are lower than expected, even if they are within the 8. These events may still be happening, but they might not reflect in reporting. Learn more here.

The impact of iOS14 update on Facebook Ads

When Apple rolled out the iOS14 update, we decided to keep an eye on the ad performance and compare the results one week before and after the update became available.

We focused our analysis on two key metrics that you can see on the graphs below – Customer Acquisition Cost (CAC) and Conversion Rate (CR). 

How to read the following graphs:

  • Each data point on the graph = the CR or CAC of a specific ad account
  • The horizontal, x-axis = the results in the 7 days before the update and reading 
  • The vertical, y-axis = the results in the 7 days after the update that happened on April 20. 
conversion rate comparison before and after the iOS 14 update
cac comparison before and after iOS 14 update

If the blue dots fall on the red line, it means that the CR/CAC was the same in the week before and the week after the update.

We can see that this was actually the case in the majority of the accounts analyzed, as most of the blue dots fall close to the red line.

Had the effects of the updates been significantly bad, we’d see a lot of these data points under the red line, indicating better results before the update than they were after the update.

Since this is not the case, we see that in the first week after the update, we’ve seen no significant bad changes to the conversion rate and customer acquisition cost and in some instances, we’ve detected better results after the iOS 14 update.

Your turn

Have you started seeing the impact of the iOS 14 update on your results? We’d love to know your thoughts on this so feel free to leave a comment below. 

For more blog posts on Facebook advertising and the latest industry trends, be sure to check out our blog

Recommended Posts

No comment yet, add your voice below!

Add a Comment

Your email address will not be published.