If you're staring at your Google Ads account this week and wondering whether AI Max is performing or tanking, stop comparing September numbers to August ones as if the reporting layer is identical. It isn't.
The September 1 migration didn't just flip a switch on campaign settings. It changed what your search terms report shows and how it categorises the data coming in. Before you tell anyone that performance is up or down, make sure you're reading the same report format you were reading before.
Three things that changed in your search terms report
According to Search Engine Land's coverage of the AI Max upgrade and Google's own help documentation, the migration introduced three specific changes to the search terms report.
First, AI Max is now a distinct match type in the report. Alongside Exact, Phrase, and Broad, you'll see AI Max as its own category. That distinction matters — it tells you which impressions came specifically from keywordless matching rather than from any keyword you explicitly set. Previously you couldn't see that split.
Second, a new source column was added that separates traffic into keyword-driven, Broad Match expansion, and keywordless matching. This is genuinely useful data. It lets you see what proportion of your new impression volume is coming from pure AI Max expansion versus the expanded reach you'd get from standard broad match anyway. That's a question that was unanswerable before September 1.
Third, the report now shows a combined view: the search query, the ad headlines that served against it, and the destination URL in a single row. This is the first time you can see the full creative context alongside the query. A term that looks irrelevant in isolation can look entirely different when you see which headline matched against it. That context should change how you add negatives.
The language targeting change is also coming in late September
Starting in late September 2026, Google will remove campaign-level language settings from Search and AI Max for Search campaigns. Per coverage from Search Engine Journal and ppc.land, Google will instead match ads based on the language of the creative and the landing page, along with its own modelling of the languages a user reads.
If you run multilingual campaigns, this is a structural change worth auditing now. Confirm that your landing pages are clearly in the intended language and that your ad copy doesn't create ambiguity about which language the campaign should serve.
Performance Max is partially exempt. Ads served on Google Search through PMax will follow the new automated language matching, but other PMax placements — YouTube, Display, Discover, Gmail — continue to honour your existing language settings. Different rules, same campaign.
What week-one data actually tells you
Not much, and that's not a bad thing.
Google's Smart Bidding goes through a calibration phase after any structural change. The first 7 to 10 days of AI Max data are unreliable for making definitive calls about performance direction. If your account runs fewer than 30 conversions per week, extend that calibration window to three weeks.
What week one IS useful for:
Verify that brand exclusions carried over correctly. Run your own brand terms in the search query filter and confirm they're excluded where they should be. Google says these transfer automatically; this is the week to verify that claim, not October.
Use the new source column to understand the composition of your traffic, not the quality of it. A high volume of keywordless AI Max impressions is expected and not alarming by itself. Whether those impressions convert is a question you can't answer with five days of data.
Don't benchmark CPA yet. Benchmark the direction of traffic composition instead.
Setting up a proper comparison for Q4 planning
The October planning window opens for most brands in the next few weeks. Making budget and bidding decisions while your AI Max migration is under two weeks old means building strategy on an unreliable baseline.
The right approach: document August 31 as your pre-migration snapshot. Pull a search terms export, a conversion path report, and your top-line impression share data for the period ending that date. Then build your comparison period starting September 15 or later, after Smart Bidding has had time to stabilise.
The new report columns — the AI Max match type, the source breakdown — won't appear in August data because they didn't exist then. Any automated platform comparison you run across that date boundary will be incomplete. Build the comparison manually, or you'll be comparing data that isn't structured the same way.
If you want to see where your account's conversion tracking and bidding signal sit before Q4 planning starts, the free audit at gromerce.com/audit surfaces those gaps in a few minutes.
Week one of AI Max tells you less than you think — but the new report structure tells you quite a bit, if you know what columns to look at.
Sources: Search Engine Land, Search Engine Journal, ppc.land, Google Ads Help, September 2026
