What is Meta's Aggregated Event Measurement?
Aggregated Event Measurement is Meta's protocol for measuring web and app events from people on iOS 14 and later. It removes identifiers, adds differential privacy and aggregates data across users. For website campaigns, Meta has dropped the old setup work: no ranking of 8 events per domain, and no Events Manager tab.
Aggregated Event Measurement, or AEM, is the system Meta uses to measure conversions from people on iOS 14 and later devices while protecting their privacy. For website advertisers, the part that used to take work, prioritizing 8 conversion events per domain, is no longer needed. The protocol still runs in the background, and Meta says it will keep evolving.
What does Aggregated Event Measurement do?
Meta describes it as a protocol that lets it measure web and app events from people on iOS 14 and later devices. Before it personalizes ads or measures how they perform, it removes identifiers, adds differential privacy and aggregates the data across users. For websites, Meta says it helps recover limited measurement of conversions from people on iOS 14.5 and later.
Since 9 October 2024, Meta has also sent AEM reporting to mobile measurement partners, with the same privacy steps applied, so app advertisers can see it in those partners’ reports. Meta says integration times vary by partner.
What changed for website campaigns?
Meta now says there are no steps you need to take for your events to be processed through AEM. It lists these changes for accounts that have the update:
| Old setup step | What Meta says now |
|---|---|
| Prioritize 8 conversion events per domain | No longer needed for web conversion optimization |
| Turn on value sets to use value optimization | No longer needed |
| Aggregated Event Measurement tab in Events Manager | Removed, since web events no longer need configuring |
| Verify your website domain for event configuration | Not required, though you may still need it for other reasons |
| Select a conversion domain when creating a campaign | No longer needed in Ads Manager |
Meta frames these as changes “you’ll see when you have access”, so check your own Events Manager rather than assuming every account switched at once.
What changed for app campaigns?
Meta is rolling these updates out to app campaigns gradually:
- AEM now covers campaigns with the App promotion objective, so you can run them without configuring app events for Apple’s SKAdNetwork. You can still configure SKAdNetwork if you want cross-platform reporting.
- iOS 14+ campaigns that use AEM as the attribution method get near real-time reporting.
- Those campaigns get 1-day click and 7-day click reporting, and 7-day click attribution windows plus Audience Network delivery, for app event and value optimization.
With a mobile app as the destination, Meta says AEM currently supports sales campaigns with the catalog on or off, lead campaigns and engagement campaigns. It doesn’t support custom event optimization. You may need to take action to make your app eligible; Meta says to check eligibility in Events Manager.
Does it apply to Conversions API events?
Yes, it can. Meta notes that events you send through the Conversions API may also be processed according to the limits AEM sets.
FAQ
Do I still need to rank 8 events for my website?
No. Meta’s help page says you no longer need to prioritize 8 conversion events per domain for web conversion optimization, and the Aggregated Event Measurement tab has been removed from Events Manager.
Is Aggregated Event Measurement switched off?
No. Only the manual setup for website events went away. Meta still describes AEM as the protocol for measuring web and app events from iOS 14 and later devices, still processes events through it, and says it will continue to evolve to support consumer privacy.
Do I still need to verify my domain?
Not for configuring events. Meta says domain verification is no longer required for event configuration, but you may still need it for other purposes, such as controlling who can edit links in ads that point to your site, or completing business verification in some cases.
Sources
- About Meta's Aggregated Event Measurement (Meta, checked 2 Oct 2026)
- When to use domain verification to verify your business (Meta, checked 2 Oct 2026)
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