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Preparing our Partners for iOS 14: Actions for Partners and Mobile Web Advertisers

Updated on April 26, 2021: On Tuesday, April 27, 2021 Facebook will begin rolling out new ad measurement protocols --Apple’s SKAdNetwork API and Facebook’s Aggregated Event Measurement -- following the release of iOS 14.5. Advertisers and partners will then begin to experience the changes described in this blog post. For the latest update visit the Facebook for Business blog.

Updated on April 21, 2021: On Tuesday, April 20, 2021, Apple confirmed that the release of general availability of iOS 14.5 will begin next week, and that it will start requiring apps in the App Store to obtain permission to “track” users across apps and websites owned by third parties for advertising and measurement purposes through it’s App Tracking Transparency (ATT) prompt. Apple’s prompt requirement will also prohibit certain data collection and sharing by businesses unless people opt in. As part of these changes, we’re implementing new ad measurement protocols, including Apple’s SKAdNetwork API and Facebook’s Aggregated Event Measurement and the changes described in this blog post will begin rolling out with the expected general availability of iOS 14.5 next week. We will provide an update with a specific date once more details are available from Apple. For the latest update, visit the Facebook for Business blog.

Today, January 19, we are providing an update to our earlier guidance to prepare you for the changes created by Apple’s iOS 14 requirements. We’re launching new experiences in our advertising tools that will guide you through some of these changes, including some of the actions you will soon be able to take. While Apple has still not made it clear to the industry when they will enforce their AppTransparencyTracking prompt, we are taking advance steps to help prepare you and reduce disruption to your advertising and integrations across Facebook apps.

Please note if you use the Ads Insights API, there will be an immediate change to measurement beginning today. Please see details below.


We will launch Resource Center, a dedicated tab in Ads Manager with a customized checklist of tasks to guide advertisers through specific actions to ensure your advertising is set up optimally and prepare for the upcoming impact of iOS 14 requirements.

The Resource Center will provide a list of relevant updates summarizing how iOS 14 requirements may impact your specific ad account. Most tasks and updates will link to Help Center articles to further support you through these changes.


Beginning today, advertisers will be able to view all their events through new tabs in Events Manager, “Pixel/Conversions API” and “Aggregated Event Measurement.” The Aggregated Event Measurement tab will provide information on web events processed using Aggregated Event Measurement. Pixel/Conversions API tab Full data events includes all other web events that are not limited by Aggregated Event Measurement. Initially, the Aggregated Event Measurement tab will include events autoconfigured for the accounts domains based on an accounts ad activity.

Advertisers will be able to edit and prioritize the automatically configured events for a given domain in a new event configuration tool in Events Manager.

Below you will find previous guidance and additional details provided for Aggregated Event Measurement and Event Limits.

Aggregated Event Measurement: Facebook will introduce Aggregated Event Measurement to support measurement of web events from iOS 14 users once Apple requires the ATT prompt. It is designed to help you measure campaign performance in a way that is consistent with consumers’ decisions about their data.

Event Limits: You will be limited to the use of 8 conversion events per domain (i.e., 8 <pixel, event> or <custom conversion> per domain) for campaign optimization. You will not need to make changes to the pixel or your Conversions API implementation as event selection will be done in Events Manager.

  • Ahead of the prompt enforcement, advertisers will be able to view, edit and prioritize the 8 conversion events for a given domain.
  • Prior to enforcement, configuring the 8 conversion events for a domain will not impact optimization or reporting
  • At the time of enforcement, ad sets optimizing for a conversion event that is no longer available will be paused.
  • The 8 conversion events per domain will be ranked based on priority. If multiple events are completed by a user (i.e. “add to cart” and “purchase”) only the higher prioritized event will be reported.

Actions to take now:

Domain verification in Business Manager: We recommend that all advertisers verify their domain using the steps outlined in the Facebook Help Center. However, if a domain has pixel events owned by multiple Business Managers or ad accounts, one Business Manager is required to verify the domain in order to edit the event configuration.

Note: Domain Verification must be done at the effective top level domain plus one (eTLD+1 ). For example, for, and the eTLD+1 domain is

Plan for 8 conversion events per domain: If you use more than 8 conversion events per domain for optimization prepare an action plan for how to operate with 8 conversion events per domain based on your business priorities. You will not need to make changes to the pixel or Conversions API implementation as event configuration will be done in Events Manager.



  • VO will transition from Ads Manager to Events Manager and value set will need to be enabled.
  • If you have previously used VO, value sets will be automatically assigned based on historical data and turned on in Events Manager.
  • If you are eligible and use VO infrequently or have never used it, value sets must be configured manually.
  • You will be able to have a maximum of 8 value sets. Note: turning on value sets will automatically utilize 4 out of the 8 events allowed for campaign optimization and reporting for a given domain.
  • For optimal performance, events with value sets turned on should be placed in higher priority slots within the Events Manager.

Actions to take now:


There are no specific changes for Dynamic Ads for Retargeting, but you may see performance and audience sizes decrease. We expect minimal impact to you using Dynamic Ads to reach Broad Audiences.

Actions to take now:

  • Verify product URL domains in the catalog feed and avoid the use of URLs redirecting users to a different domain.
  • Prepare to use only 1 pixel per catalog to optimize for prioritized conversion events across all catalog items.


Ads Reporting (Ads Manager, Ads Reporting, Ads Insights API):

The changes outlined below will be going into effect January 19, 2021.

  • We will be replacing the account level attribution window with a new attribution setting at the ad set level accessed during campaign creation and ensures that the conversions we measure are the same ones that inform campaign optimization, allowing for increased clarity when analyzing ad performance. This setting will also be available to query via the Ads Insights API. Please reference the recent Ads Insights API blog post for more information on two new fields related to attribution settings that can be used: use_unified_attribution_setting and attribution_setting.
  • To prepare our advertisers for upcoming changes resulting from Apple’s enforcement of their AppTrackingTransparency (ATT) prompt, beginning January 19, 2021, we will initially default to a 7-day click and 1-day view attribution setting. Due to limitations around view-through signal, the attribution setting for newly created campaigns after prompt enforcement will default to 7-day click instead of 7-day click and 1-day view.
  • Any active campaigns along with future campaigns will report and optimize on the new attribution setting. While these changes don’t impact ad delivery and we will not change the optimization window for any active campaigns, the new default attribution setting may result in a decrease in the number of reported conversions, especially for advertisers who have currently opted for reporting based on longer attribution windows like 28-day click and 1-day view.
  • Until Apple begins to enforce their App Tracking Transparency (ATT) prompt, you can continue to access data for all existing attribution windows (such as 28-day click, 28-day view, 7-day view) with the comparing windows feature. Once Apple enforces their ATT prompt, we will no longer support 28-day click, 28-day view and 7-day view windows and historical data for deprecated attribution windows will only be accessible via the Ads Insights API.
  • Statistical modeling will be used for certain attribution windows and/or metrics to account for less data availability from iOS 14 users. In-product annotation will communicate when a metric is modeled.
  • Certain attribution windows will have partial reporting and metrics will not include all events from iOS 14 users. In-product annotation will communicate when a metric is partial. This will launch in early 2021 upon Apple’s enforcement of their ATT prompt.
  • Delivery and action breakdowns will not be supported for offsite conversion events.
  • Offsite conversion events will be reported based on the time the conversions occur and not the time of ad impressions. As a result, you may notice small fluctuations in cost metrics, as cost per conversion will reflect spend over a given period divided by conversions that took place over the same period, whereas today, cost per conversion reflects spend over a given period divided by conversions driven by ad impressions that took place over the same period.

For automated rules: In early 2021, attribution window settings for existing and newly created automated rules will no longer be supported, and a default window of 7-day click-through for non-iOS conversions and the SKAdNetwork window for iOS conversions will be implemented.

Actions to take now Specify attribution window changes (deprecation of 28-day click-through, 28-day view-through, and 7-day view-through windows):

  • Leverage the Comparing Windows feature to see how conversions attributed to ads compare across different attribution windows. This allows you to better anticipate the impact to reported conversions as a result of upcoming attribution window changes.
  • Update any automated rules currently using a 28-day attribution window to prevent any unexpected adjustments in spend once the new 7-day click-through window default goes into effect.

DEVELOPER APIs (Marketing API, Ads Insights API, Targeting API)

Please review the most recent guidance published here.

For information on iOS 14 impact to App based developers please see our separate Developer blog post here.

For information on how to plan for changes to our Marketing & Ads Insights API, please see our blog post here.