When Did Meta Change Its Attribution Windows?

Meta’s pages date two changes. A developer post of 14 January 2021 says the Insights API would default to 7-day click and 1-day view, not 28-day click and 1-day view, from 19 January 2021. A post of 16 October 2025 says 7-day view and 28-day view stop being returned on 12 January 2026. Meta’s help page also says the Ads Manager default for new ad sets changed, but gives no date.

What is the timeline from Meta’s pages?

Date	Meta page	What it says
14 January 2021	Developer blog	From 19 January 2021, API reports with no window specified use 7d_click and 1d_view, not 28d_click and 1d_view.
No date given	Help page	The default for new ad sets in Ads Manager changed to 7-day click or 1-day view.
16 October 2025	Developer blog	From 12 January 2026, 7d_view and 28d_view are no longer returned by the API.

What did Meta change in January 2021?

The post “Preparing our Partners for iOS 14” says changes on 19 January 2021 “will result in immediate changes to your current campaign reporting, if you are not already specifying specific attribution windows”. Its wording: “If you do not provide action_attribution_windows when pulling results we will use 7d_click and 1d_view by default instead of 28d_click and 1d_view.”

The post also says that when Apple enforces its tracking prompt, Meta “will update the default to 7d_click only”. It does not say whether that second change happened.

If you pull data through the API, name your windows in every request. Then a default cannot change your numbers.

What does Meta’s help page say about the Ads Manager default?

Meta’s page on how conversions are attributed in Commerce Manager says: “the default attribution setting for all new ad sets was changed to 7-day click or 1-day view.” Its options are 1-day click, 7-day click, 1-day click or 1-day view, and 7-day click or 1-day view (default).

For active ad sets, the page says the setting “will continue using the deprecated conversion window setting to avoid impact to ad delivery”. It warns that reported conversions may fall for advertisers who used an account-level window that is no longer available, “like 28-day click and 1-day view”. The page gives no date, so this entry gives none.

So two ad sets in one account can use different windows. Open each ad set’s attribution setting before you compare them.

What changed in January 2026?

The 16 October 2025 post says that on 12 January 2026 the Ads Insights API’s action_attribution_windows parameter stops returning 7-day view (7d_view) and 28-day view (28d_view).

It says that, “consistent with Ads Manager behavior”, 1-day click, 7-day click, 28-day click, 1-day engaged view and 1-day view continue to be available for fields like actions, conversions and results.

Which windows does Meta list today?

Meta’s attribution page lists these standard settings for website and in-store conversions:

• Click-through: events within 1 day or 7 days after a link click.
• View-through: events within 1 day after an impression.
• Engage-through: events within 1 day after a non-link-click action.

Meta’s compare tool also lists 28-day click, and says it shows partial data if your campaign has run for fewer than 28 days.

Do Meta’s pages agree about 28-day click?

Not fully. The 2021 post says that when its changes take effect, Meta will no longer support offsite web conversion metrics over 7d_view, 28d_view and 28d_click, while historical data stays available. The 2025 post lists 28-day click as continuing, and the compare tool lists it too. Meta does not explain the gap.

Before you rely on 28-day click, check what your own account and API calls return.

What should you check in your account today?

• Open each active ad set and note its attribution setting. Old and new ad sets may differ.
• Export a comparison with the compare attribution settings tool, so you see 1-day click, 7-day click and 1-day view side by side.
• Search your saved reports and scripts for 7d_view and 28d_view, and name your windows in every API call.
• Keep one window fixed when you compare periods before and after 12 January 2026.

FAQ

Did the new default apply to every ad set?

Meta’s help page says only new ad sets got the new default. Active ad sets keep the deprecated setting so delivery is not affected. Older and newer ad sets may therefore report on different windows, so check each one.

Why do my old and new reports not match?

Meta’s pages describe two shifts that could do it: API reports with no named window changed default on 19 January 2021, and, per Meta’s October 2025 post, 7-day and 28-day view were due to stop being returned by the API on 12 January 2026. Meta’s pages do not diagnose your account. Compare reports that use the same named windows.

Which attribution window should I use now?

Meta’s pages do not say. They list click-through of 1 or 7 days, view-through of 1 day and engage-through of 1 day as standard settings. Pick the window that fits how long your buyers take to decide, then keep it fixed when you compare periods.