Meta API v27 lets your iOS ad sets buy Android by default

An iOS-only Sales ad set used to mean iOS-only delivery. From Marketing API v27.0, released on 4 November, a new Sales ad set that targets an operating system or specific devices can also deliver to other devices and operating systems, unless the request that creates it says no. In about 90 days the same default applies on every API version, so staying on v26 only delays it.

The same release changes a second default. Meta may now add Product showcase, products from your catalog under the ad, to new ads whose creative says nothing about it.

What Meta changed

The release post lists both defaults under “Key dates and changes”:

• Reach more people across other mobile devices. On new eligible Sales ad sets that target user_os or user_device, the setting targeting_automation.individual_setting.device now defaults to 1. Meta can then deliver “to people on other mobile devices and operating systems when that is likely to improve performance”. Existing ad sets do not change. Ad sets that use the Mobile App conversion location or a Special Ad Category are not eligible.
• Product showcase. When a creative has no product_extensions setting, Meta may turn it on if it has “high confidence” that a product set in your catalog matches the ad. This applies to ads and creatives created on v27.0. Older versions do not change.

The release also stops accepting country and location_spec in a lookalike spec, ends the /{catalog-id}/batch endpoint on v27.0, and removes the total_video_consumption_rate video metric on every version. Graph API v21.0 is removed on 21 January 2027.

The detail in the reference page

The Advanced targeting reference, updated for v27, has a rule that the release post leaves out. If an update replaces an ad set’s whole targeting object and does not include device, the stored value is cleared. A tool that writes the full targeting object on every edit can delete your device: 0 without anyone deciding to. The page says a cleared field reads back as “never set” and that the default applies only at creation. It does not say how such an ad set then delivers. Read the field back after each edit and do not assume.

The Product showcase change also reverses an earlier rule. Meta’s product-extensions page, last updated in January 2025, says that since v20.0 every eligible ad creation request must state OPT_IN or OPT_OUT. From v27, a request that leaves the field out is accepted, and Meta can decide for you.

The read

An ad set’s device targeting no longer tells you where it delivered. Advertisers split ad sets by OS for good reasons: iOS and Android buyers can have different order values, and after Apple’s App Tracking Transparency changes, iOS results are often measured differently. Until now, the CPA of an iOS ad set was the CPA for iOS. On a new ad set created through v27, it is a blend of iOS and whatever Meta added, and the ad set name still says iOS.

The reports can check part of it, not all of it. Meta’s Insights API has a device_platform breakdown, which only says mobile or desktop, and an impression_device breakdown, which reports the device where the last ad was served. It has no operating-system breakdown. Since 6 August, impression_device can return nothing in a synchronous request for some accounts until an admin opts in, so a dashboard that does not show it may be missing data rather than showing zero. And the device that saw the ad is not always the one that bought: a person who saw the ad on an Android phone and bought on an iPhone is counted under impression_device as Android.

The default goes to whoever does not send the field. Nobody in Ads Manager accepts this change. Any tool, script or agency platform that creates Sales ad sets through the API and does not send device gets the expansion on v27 now, and on every version from about February. The same is true for Product showcase on v27: an ad creative made by a tool can show catalog products that nobody chose.

What to do

1. Send device: 0 on every ad set that must stay on its devices, and send it again on every update that rewrites the whole targeting object. Read targeting{targeting_automation{individual_setting{device}}} back to check.
2. Send enroll_status: OPT_OUT in the creative features spec on any ad that must show only the creative you made, for example a single-product ad or an ad with regulated claims.
3. Add impression_device to the device-split ad sets you report on. Use an asynchronous report job if the synchronous request comes back empty.

Meta’s case for the default is that it improves performance. The only way to check that in your own account is to run the same ad set with the setting on and off and compare the results. That leaves the question of how much a lift result can be trusted. Ads that do nothing get a lift result half the time tests that on Google’s own certainty measure.