Google's AI Max for Search: What It Is and Whether You Should Use It

On 1 September, Google started automatically upgrading eligible Search campaigns to AI Max. If your account uses Automatically Created Assets or campaign-level broad match and you didn't explicitly opt out, there's a good chance you're running AI Max right now, whether you noticed or not.

It's easy to shrug this off as another Google rebrand. It's not. AI Max fundamentally changes how Search campaigns match queries, generate ad copy, and route traffic. If you don't know what's on by default, you're not really managing the account any more. You're supervising Google's algorithm and hoping it behaves.

Here's what AI Max for Search actually does, when it earns its keep, and when to switch it off.

What AI Max for Search actually does

AI Max is a bundle of three features layered on top of your existing Search campaigns:

• Search term matching. Google uses AI signals to serve your ads on queries beyond your keyword list. In practice, it's broad match with extra machine learning on top.
• Text customisation. Google generates its own headlines and descriptions using content pulled from your landing pages.
• Final URL expansion. Google can redirect a click to a different page on your site if it decides that page is a better match than your original landing URL.

You activate the full suite with one toggle. Some of it is already on by default. Automatically Created Assets and campaign-level broad match now trigger the AI Max upgrade automatically. Dynamic Search Ads get force-migrated from February 2027, so if you're still running DSAs, that's on the clock too.

Google's own pitch on the feature suite is that campaigns using the full stack see 7% more conversions or conversion value at a similar CPA/ROAS versus using search term matching on its own. That's the number to keep in your head. Not "revolutionary", not "game-changing", just 7%.

Why Google keeps pushing this

The overall theme? Google wants advertisers using their AI tools. You can fight it or work with it, but the direction of travel is clear.

There's a commercial reason underneath. Roughly a third of Google searches don't map cleanly to any advertiser's keyword list, and AI Max is Google's way of monetising those queries at scale without needing you to build the campaigns for them. It also lowers the barrier for advertisers who don't want to think too hard about structure, which is nice for Google's total addressable market but not always great for individual account performance.

Interestingly, Google has also released "AI Brief", a Gemini-powered feature that lets you provide business context to steer AI Max. Which is a quiet admission that the automation needs steering. If it worked perfectly out of the box, you wouldn't need to write it a brief.

Where AI Max actually earns its keep

Not every account should switch this off in a panic. There are situations where it does real work:

• Small accounts with limited keyword coverage. If you're running 30 keywords across three ad groups, AI Max will genuinely find intent you haven't mapped. That's not a failure of your keyword research. It's just that most businesses can't sit and write out every long-tail variation, and AI Max is decent at finding them.
• Accounts with strong landing pages. Text customisation is only as good as the source material. If your landing pages are well-written, clearly focused, and have real value propositions on them, the auto-generated headlines are usually fine.
• Verticals with high intent variation. Legal, medical, home services, financial advice - anywhere people phrase the same intent 200 different ways. The broader matching earns its keep here.
• Accounts with enough conversion volume for Smart Bidding to actually learn. If you're getting 30+ conversions a month and your tracking is clean, AI Max plus tROAS or Max Conversions has real signal to work with.

If you tick most of those boxes, leave it on and watch the numbers.

Where AI Max falls over

The trouble usually starts with Final URL expansion. Turn it on, and Google can send a click for "occupational therapy Melbourne" to your /our-team/ page instead of your OT services page. That's not hypothetical. I saw exactly this pattern in an account I audited this week - five clicks landing on the About Us page from service-intent queries, zero conversions on around $30 in spend. Sounds trivial. It's not. Multiply that across every non-service page on a busy site and you're funnelling a chunk of your budget into pages that never had a shot at converting.

The other problem spots:

• Brand campaigns. You've spent years getting your brand messaging right. Text customisation will happily improvise on it. Turn it off for brand.
• Regulated verticals. Legal, financial, medical, gambling, anything with disclaimers. Auto-generated copy is a compliance liability, not a productivity gain. Turn text customisation off and write your own.
• Multi-service businesses. Any site where different pages serve different intents - accountants who also do tax returns, plumbers who also do heating, agencies with 12 service pages - Final URL expansion becomes a wildcard. Use URL exclusions or turn it off.
• Weak negative keyword hygiene. Broader matching means more search terms to review each week. If you're not doing weekly search term reviews, you're feeding an algorithm your budget with no cleanup pass. On accounts I audit, this is usually where the waste starts stacking up - the same pattern I wrote about in how to actually reduce Google Ads waste.

What to do this week

Assuming your campaigns have already been auto-upgraded, or are about to be:

1. Open every enabled Search campaign and check the three AI Max settings: search term matching, text customisation, and Final URL expansion. Don't assume the defaults are what you want.
2. On multi-page sites, turn off Final URL expansion unless you've added URL exclusions for the pages you don't want Google routing traffic to.
3. On brand campaigns, turn off text customisation. Google should not be improvising on your brand copy.
4. In regulated verticals, turn off text customisation across the board and write your own headlines.
5. Move your search term review from monthly to weekly. Broad match got broader. If you understand how Google Ads match types actually work, you already know why this matters, but AI Max makes it more urgent, not less.
6. If you're leaving AI Max on, spend 20 minutes writing an AI Brief. Explicit context beats leaving it to Google's guess.

None of this takes long. Twenty minutes per campaign at most. The alternative is finding out three months from now that Google has quietly reallocated a large chunk of your budget to queries you'd have added as negatives if you'd seen them.

My take

My take: AI Max is essentially Google's way of pushing you towards broad match with slightly better guardrails. For accounts with weak keyword coverage or genuinely broad intent, it can find conversions you'd otherwise miss. For accounts with tight structure and well-mapped intent, it's mostly a mechanism for spreading your budget across queries you'd already decided not to bid on.

The auto-upgrade is the tell. Google isn't doing this because it helps you individually. It's doing it because it helps them monetise the queries that don't fit anyone's keyword list. That doesn't make AI Max useless. It just means you need to make an active decision about it, not a passive one.

If you're going to hand your account to an algorithm, at least do it on purpose.

Key Takeaways

• AI Max auto-upgrades started on 1 September for campaigns using ACA or campaign-level broad match. DSAs get migrated from February 2027.
• The three features are search term matching, text customisation, and Final URL expansion. Each one has its own toggle.
• Turn off Final URL expansion on multi-page sites unless URL exclusions are in place.
• Turn off text customisation on brand campaigns and any regulated vertical.
• Move search term reviews to weekly. Broader matching means waste ramps up faster than you'd think.
• Google's claim is 7% more conversions at similar CPA. Real. Not revolutionary.

If you're not sure whether AI Max is running across your Search campaigns, or you want a second set of eyes on the queries it's dragging in, that's the sort of thing I look at during a Google Ads audit. Otherwise, block out 20 minutes per campaign this week and make a deliberate call. The auto-upgrade already happened. The active decision is still up to you.