- Microsoft says early AI Max tests showed at least 8% more conversions than Search campaigns with it disabled. [1]
- The footnote: 44 advertiser-run A/B tests, June to August 2026, spend-weighted uplift of about 13.6%. [1]
- Ten of the 44 had statistically significant positive results, with a lower confidence bound of 8.2%. [1]
- AI Max is on by default in new Search campaigns, and Google Import can carry it over. [1]
- From October 1, 2026, new non-portfolio campaigns on three automated strategies lose the Max CPC setting. [2]
- Dynamic Search Ads stay supported on Microsoft until further notice. [1]
Microsoft launched AI Max for Search on August 27, 2026 with the performance claim every platform now makes about its automated search product: more conversions. [1] What it did differently was print the experiment underneath. Footnote 4 of the announcement describes 44 advertiser-run A/B tests from June to August 2026, each comparing Search campaigns with AI Max enabled against the same campaigns with it disabled, on the same bid strategy and budget. [1]
Then it gives the result in two numbers that are easy to confuse. The spend-weighted conversion uplift across the 44 advertisers was about 13.6%. And 10 experiments had statistically significant positive results on conversions or conversion value, with the lower confidence bound at 8.2%. [1] The body of the post rounds that to “at least an 8% increase in conversions.” [1]
How to read ten out of 44
Start by giving Microsoft credit. A test count, a design, a window, a weighting method, and a significance count is more than Google published behind its own AI Max figure, and more than most platform claims carry at all. It also lets you do what the headline does not: ask what a typical advertiser should expect.
Ten significant winners out of 44 means 34 tests did not produce a statistically significant positive result. The footnote does not say how many of those were flat, how many were small wins without enough data, and how many lost. [1] A spend-weighted average also leans toward the largest accounts, which tend to have the conversion volume to reach significance. So the honest summary is not “AI Max adds 8%.” It is that in a quarter of Microsoft’s own tests the gain was clear, and the rest need your data to know. The post adds that campaigns leaning on exact and phrase match saw a higher uplift, which is consistent with a product that finds queries your keyword list was missing. [1]
That is a useful thing to know before you switch it on, because Microsoft has made switching it on the default.
On by default, and inherited from Google
AI Max is optional for existing campaigns. For new ones, Microsoft says it will be enabled by default for any Search campaign you create, though it can be turned off during creation or afterwards. [1] It bundles three features: search term matching beyond your keyword list, text customization of your ads, and final URL expansion that can send a searcher to a different page of your site. [1] Existing negatives, bid strategies, budgets, and targeting still apply, and Microsoft adds brand inclusions and exclusions and term exclusions for generated text. [1] Google’s help center describes its own version around two main features, search term matching and asset optimization. [3]
AI Max travels with the import. Microsoft says AI Max settings can now be carried over from Google Ads, and with scheduled imports, Microsoft campaigns that match Google campaigns with AI Max enabled keep inheriting those settings on every sync. [1] Google has been auto-upgrading campaigns that use automatically created assets or campaign-level broad match since September 2026, so check what your next import will switch on here. [4]
DSA does not. Dynamic Search Ads remain supported on Microsoft until further notice, and DSA campaigns upgraded in Google Ads come back as standard DSA campaigns on import. [1]
If you have read about Google’s AI Max migration, this is the other half of the same decision. Google is changing campaigns for you. Microsoft is making the new ones AI Max unless you say otherwise, and copying whatever Google did through the import.
October 1: the cap comes off new campaigns
The second change has a date. Starting October 1, 2026, the Max CPC setting is no longer available when you create new non-portfolio campaigns on three automated strategies. [2]
| Campaign | Max CPC after October 1, 2026 |
|---|---|
| New, non-portfolio, Maximize Conversions with Target CPA | Not available [2] |
| New, non-portfolio, Maximize Conversion Value with Target ROAS | Not available [2] |
| New, non-portfolio, Maximize Clicks | Not available [2] |
| Existing campaigns created before October 1 that already use it | Kept [2] |
| New and existing campaigns on portfolio bid strategies | Still available [2] |
Microsoft’s reasoning is that a Max CPC overrides your own CPA or ROAS target, gives the system conflicting instructions, and makes advertisers miss their outcomes even when the cap sits above the average cost per click. [2] It recommends steering with budgets, targets, conversion value rules, and seasonality adjustments instead, and suggests using experiments to see what removing the cap does. [2]
There is a practical reading of that table. If you rely on a CPC cap as a safety rail in volatile auctions, the rail still exists for campaigns you already have and for anything on a portfolio strategy. Build new campaigns that need it inside a portfolio, or accept that the target is now the only lever. Either way, do it before October 1, when the choice disappears for new standalone campaigns.
What to do with both changes
Run the test Microsoft ran. The platform’s experiments tool duplicates a Search campaign, gives the copy a share of the original’s budget and traffic, recommends a 50/50 split, and shows a metric in gray when the difference is not statistically significant. [5] Change one thing in the copy, AI Max on, and the result is the only version of the uplift figure that describes your account. [1] Two limits: experiments do not work with shared budgets or on campaigns with Dynamic Search Ads settings. [6] Give the test enough conversions to reach significance, because 34 of Microsoft’s 44 did not. Keep AI Max off on new campaigns until the split says otherwise, and read your import settings before the next scheduled sync decides for you.
Sources
- Microsoft Advertising · Reimagining Search campaigns for the AI era with AI MaxAugust 27, 2026, by Carolyn Chou. The three features, the default for new campaigns, Google Import behavior, DSA support, and footnote 4 with the 44 experiments.
- Microsoft Advertising · AI Max for Search and other product news for August 2026The October 1, 2026 Max CPC change, which campaigns keep the setting, and Microsoft’s reasoning.
- Google Ads Help · How AI Max for Search campaigns worksGoogle’s description of its version around search term matching and asset optimization.
- Google Ads & Commerce Blog · We’re upgrading Dynamic Search Ads to AI MaxApril 15, 2026, with a later update: campaigns using automatically created assets and campaign-level broad match auto-upgrade from September 2026, and the DSA auto-upgrade moved to February 2027.
- Microsoft Advertising Help · Discover the possibilities with experimentsThe duplicate campaign, the budget and traffic split, the 50/50 recommendation, and how significance is shown.
- Microsoft Advertising API · Experiment Data ObjectUp to 10 nonconcurrent experiments per base campaign, and the exclusions for shared budgets and Dynamic Search Ads settings.
Frequently asked questions
What is AI Max in Microsoft Advertising?
An optional suite of Search campaign features that Microsoft says combines three capabilities: search term matching beyond your keyword list, text customization of your ads, and final URL expansion to other pages on your site. It respects existing negative keywords, bid strategies, budgets, and targeting, and adds brand inclusions and exclusions.
How much does AI Max improve results?
Microsoft says advertisers in early tests saw at least an 8% increase in conversions versus control Search campaigns with AI Max disabled. Its footnote describes 44 advertiser-run A/B experiments from June to August 2026, a spend-weighted conversion uplift of about 13.6%, and 10 experiments with statistically significant positive results on conversions or conversion value, with a lower confidence bound of 8.2%.
Is AI Max on by default?
For new Search campaigns, yes. Microsoft says AI Max will be enabled by default for any new Search campaign, though you can turn it off during creation or afterwards. For existing campaigns it is optional.
Does Google Import turn AI Max on?
It can. Microsoft says AI Max settings can now be carried over from Google Ads, and that with scheduled imports, Microsoft campaigns that correspond to Google campaigns with AI Max enabled will keep inheriting those settings on future syncs.
What changes with Max CPC on October 1, 2026?
From October 1 the Max CPC setting is no longer available when creating new non-portfolio campaigns using Maximize Conversions with Target CPA, Maximize Conversion Value with Target ROAS, or Maximize Clicks. Existing campaigns created before October 1 keep it, and portfolio bid strategies keep it for new and existing campaigns.
Why is Microsoft removing Max CPC?
Microsoft says a Max CPC overrides the advertiser’s own CPA or ROAS targets, gives the system conflicting instructions, and causes advertisers to miss their desired outcomes even when the cap is above average CPC. It recommends budgets, targets, conversion value rules, and seasonality adjustments instead, and suggests using experiments to test removing the cap.
Is Microsoft retiring Dynamic Search Ads like Google?
No. Microsoft says DSA campaigns will continue to be supported in Microsoft Advertising until further notice, and that DSA campaigns upgraded in Google Ads are converted back to standard DSA campaigns when imported.
Mikołaj Salecki
Writes about media, tech, and AI business for people who actually run digital. Former agency lead. Skeptic of frameworks that read better than they perform.
