A small business owner logs into Google Ads in October and notices something odd in the search terms report. Her ads for a plumbing service are appearing on searches she never targeted, some sensible, some not. Her headlines include lines she didn't write. Spend is up a little, conversions are up a little, and she never clicked anything that agreed to this. She is not imagining it. During September, Google moved her Search campaign to AI Max.
For many advertisers, the migration happened quietly in the background, and plenty of accounts are still running on whatever settings Google chose for them. The instinct is either to panic or to ignore it. Neither helps. The more useful way to see it is this: you didn't choose AI Max, but you still choose how it runs. Control hasn't disappeared; it has moved from picking keywords to shaping the inputs and guardrails the system works within.
This post covers the September 2026 migration of Search campaigns. The separate Dynamic Search Ads migration, scheduled for February 2027, will be covered in its own guide. For background on how keywordless search advertising developed, see Google's AI-powered search campaigns.
What actually happened
Google set out the timeline in advance, and it played out in three stages. From 3 August 2026, advertisers could no longer create new Search campaigns using the campaign-level broad match setting or legacy automatically created assets. Between 1 and 30 September, existing campaigns using either of those settings were upgraded to AI Max automatically, migrated in place with equivalent settings. There was no opt-out, and a migrated campaign cannot be switched back. Existing brand inclusions and exclusions carried over.
Two other changes landed alongside it. Google began showing in-account notices encouraging advertisers to upgrade Dynamic Search Ads voluntarily ahead of a mandatory migration in February 2027. And in late September, Google began removing the campaign-level language setting from Search and AI Max campaigns, which matters particularly for businesses advertising in more than one language.
What turned on, and what didn't
AI Max bundles three features, and not every migrated campaign received all of them. What changed in your account depends on how each campaign was set up before September.
| Before September | What was switched on | Check first |
|---|---|---|
| Campaign-level broad match | Search term matching | Search terms report and negatives |
| Automatically created assets | Search term matching and text customization | Generated headlines and descriptions |
| Neither setting | Nothing forced; AI Max optional | Language setting changes |
| Dynamic Search Ads | Notices now; migration February 2027 | Plan the move deliberately |
Search term matching lets Google show your ads on searches it predicts are relevant beyond your keyword list, including queries none of your keywords would have matched. Text customization, the successor to automatically created assets, generates headlines and descriptions from your existing ads, keywords and landing pages. Final URL expansion, which lets Google send a click to whichever page on your site it judges most relevant, was not switched on by default for either group. In practice, your keywords now behave more like signals of intent than strict fences.
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Why this is really a shift in where control lives
For years, search advertising gave marketers direct control: choose the keywords, choose the match types, write the ads, pick the landing page. AI Max moves much of that to the system. What you still control, and control more than ever, is what the system learns from and where it is allowed to go.
That means five inputs deserve more attention than they used to. Conversion data, because the system optimises towards whatever you tell it counts as success, so inaccurate or low-value conversion tracking steers it in the wrong direction; the setup is covered in conversion tracking you can trust. Negative keywords, now the main way to fence off irrelevant queries, as covered in the complete guide to negative keywords. Brand controls, which decide whether you appear on your own and competitors' brand searches. Landing pages, which text customization reads and which shape relevance. And account structure, which decides where AI Max explores and where you keep tight control, as set out in structuring a Google Ads account for scale and control.
The shift You didn't choose AI Max, but you still choose how it runs. Control hasn't disappeared. It has moved from picking keywords to shaping the conversion data, negatives, brand controls and landing pages the system works within.
A post-migration audit in five steps
1. Find out what changed. Check which campaigns now show AI Max, and which features each has switched on. Note the date each migrated, since before-and-after comparisons depend on it.
2. Read the search terms report. Filter for queries that came from AI Max and sort by spend. Most will be sensible extensions of your keywords; some won't. Add negatives for the irrelevant ones, and look for promising new themes worth turning into keywords of their own.
3. Review generated text. For campaigns that used automatically created assets, open the asset report and read every Google-generated headline and description. Remove anything inaccurate, off-brand or non-compliant; generated text can't be edited in place, but it can be removed, and text customization can be switched off entirely if it doesn't suit your brand or regulated category. Treat good generated lines as ideas for your own ad testing, using the discipline in ad creative testing.
4. Check brand and language settings. Confirm brand inclusions and exclusions carried over as intended, and review any multilingual campaigns now that campaign-level language targeting is being removed.
5. Decide your structure. Many advertisers now keep a tightly controlled campaign for their most important, highest-intent terms and let AI Max campaigns explore more broadly around them. That gives you a stable core and a clear way to measure what the expansion adds. It mirrors the balance many teams already strike with Performance Max.
Judge it on marginal cost, not the average
The most common mistake after the migration is looking only at the blended cost per acquisition. If it looks roughly the same, everything seems fine. But the average can hide expensive extra conversions.
Before migration: $10,000 a month buys 250 conversions → $40 each.
After migration: spend rises to $12,000 and conversions to 285 → blended cost about $42.
The blended figure looks almost unchanged. But the extra $2,000 bought only 35 extra conversions → about $57 each.
The question that matters: is $57 still below the most you can afford to pay for a conversion? If your break-even is $60, the expansion is earning its keep. If it's $45, the extra reach is losing money, even though the average looks fine.
Compare like with like: match equivalent periods, account for seasonality, and check the quality of the extra conversions as well as their number.
Give the system a few weeks of stable settings before drawing firm conclusions, since major structural changes can trigger a new learning period and performance may take time to settle. Also, be careful about reading too much into November and December, when festive and holiday demand distorts every comparison. The budgeting principles in setting and scaling ad budgets and peak-season paid media help here, and so does remembering that platform-reported numbers are only one view, as argued in why attribution is getting harder.
Landing pages matter more now
With text customization reading your pages to write ad copy, and search term matching sending more varied queries to them, landing pages carry more weight than before. A page that clearly answers the queries you want, in the language buyers use, gives the system better material and converts the broader traffic more reliably. A thin or vague page does the opposite. That makes landing page testing a natural companion to the migration, whether through post-click optimisation or the fundamentals in CRO for beginners. If final URL expansion is ever switched on, use URL exclusions to keep traffic away from pages that shouldn't receive it, such as careers or support pages.
What this signals for 2027
The migration is part of a clear direction. Google is steadily moving advertisers from manual controls to automated systems across Search, Shopping and Performance Max, and the Dynamic Search Ads migration in February 2027 continues the same path. Advertisers who adapt well will spend less time managing keywords and more time on the things automation depends on: clean conversion data, strong landing pages, clear brand guardrails and honest measurement. Businesses that want help setting those up often work with a specialist performance marketing team.
The short version
From 3 August 2026, Google stopped allowing new campaigns with campaign-level broad match or legacy automatically created assets, and between 1 and 30 September it moved existing ones to AI Max automatically, with no opt-out and no way back. Broad match campaigns received search term matching; automatically created assets campaigns received search term matching and text customization; final URL expansion was off for both. Brand controls carried over, the campaign-level language setting is being removed, and Dynamic Search Ads follow in February 2027. You didn't choose AI Max, but you still choose how it runs. Control now lives in conversion data, negative keywords, brand controls, landing pages and account structure. Audit what changed, read the AI Max search terms, review or switch off generated text, check brand and language settings, and consider a controlled core campaign alongside AI Max exploration. Judge results on marginal cost per extra conversion, not the blended average, and invest in landing pages, which now shape both relevance and ad copy.
Not sure what AI Max changed in your account?
We audit Google Ads accounts after the AI Max migration and restore control.
Explore Performance Marketing →Frequently asked questions
Which Google Search campaigns were migrated to AI Max?
Two groups of Search campaigns were upgraded automatically between 1 and 30 September 2026: campaigns using the campaign-level broad match setting, and campaigns using standalone automatically created assets. Google migrated them in place, using equivalent AI Max settings, and carried over existing brand inclusions and exclusions. There was no opt-out, and migrated campaigns cannot be switched back to the old settings. Since 3 August 2026, advertisers have also been unable to create new campaigns using those legacy options. Campaigns that used neither setting were not forced into AI Max, although they can adopt it voluntarily. Dynamic Search Ads are on a separate timeline: Google began showing upgrade notices in September, with a mandatory migration scheduled for February 2027, after which new Dynamic Search Ad groups can no longer be created. If you are unsure whether a campaign was affected, check its settings for AI Max and look for AI Max as a match source in the search terms report.
What does AI Max change in a migrated campaign?
AI Max bundles three features, and which ones were switched on depended on how the campaign was set up before. Campaigns that used campaign-level broad match were given search term matching, which lets Google show ads on searches it predicts are relevant beyond your keyword list, including queries none of your keywords would have matched. Campaigns that used automatically created assets were given search term matching plus text customization, which generates headlines and descriptions from your existing ads, keywords and landing pages. Final URL expansion, which lets Google send a click to whichever page on your site it judges most relevant, was not switched on for either group by default. In practice, keywords now act more like signals of intent than strict boundaries, so the queries your ads appear on and the words they use can both differ from what you originally set up.
Can you turn off AI Max after the migration?
You cannot return a migrated campaign to the legacy campaign-level broad match or automatically created assets settings, because those options no longer exist. What you can still do is shape how AI Max behaves. Text customization can be switched off, which removes the Google-generated headlines and descriptions from serving, and individual generated assets can be removed. Brand inclusions and exclusions, negative keywords, URL exclusions and location settings all continue to limit where ads appear. Search term reporting shows which queries came from AI Max, so you can add negatives for irrelevant ones. Advertisers who want tighter control can also restructure, for example by building separate campaigns for their most important exact and phrase match terms and keeping AI Max for exploration. The practical shift is from controlling keywords directly to controlling the inputs and guardrails the system works within.
How should you measure whether AI Max is working?
Judge it on the extra conversions it adds and what they cost, not on the blended average. Compare the period before and after migration, or AI Max-matched queries against keyword-matched ones in the search terms report, looking at spend, conversions, conversion value and cost per acquisition for each. The key number is marginal cost: if spend rose by a certain amount and conversions rose by a certain number, the cost of those additional conversions tells you whether the expansion is worthwhile, even when the overall average still looks acceptable. Check conversion quality as well, since broader matching can bring in leads or buyers of lower value. Make sure conversion tracking is accurate before drawing conclusions, account for seasonality such as the festive and holiday period, and give the system a few weeks of stable settings before judging, since major structural changes can trigger a new learning period.
