Short answer: Do not switch AI Max on across your whole account. Test it with an AI Max experiment, which splits one existing Search campaign into a control arm (AI Max off) and a treatment arm (AI Max on). Google now promotes this from the Recommendations page, and in eligible accounts it can be launched in a few clicks. Turn off the parts you are not ready for, watch the new search terms and ad combinations report, and judge the result on cost per sale or qualified lead, not clicks.
AI Max for Search is Google’s biggest change to Search campaigns in years. It can find new searches and write ad text for you, which can grow results, or quietly waste money. Here is how I test it for clients.
What AI Max for Search does
AI Max is a set of features you switch on inside a normal Search campaign. It has three main parts:
| Feature | What it does | Risk to watch |
|---|---|---|
| Search term matching | Finds searches beyond your keywords, using your landing pages and ads | Irrelevant or low intent searches |
| Text customization | Writes headlines and descriptions based on your site and ads | Claims or offers you did not approve |
| Final URL expansion | Sends people to the page Google thinks fits best | Traffic to blog posts or weak pages |
You also get brand controls and URL inclusions and exclusions to keep it in line.
Why use an experiment instead of switching it on
An AI Max experiment runs inside the same campaign instead of copying it. That avoids the usual mistakes of duplicated campaigns, such as different learning periods and split budgets. If you do not apply the result at the end, your settings return to how they were before.
How to set up an AI Max experiment
- Go to Experiments, click the plus button and choose Campaign features and settings, then AI Max for Search campaigns. You can also start from the AI Max recommendation, but read what it will apply before clicking.
- Pick one campaign with steady conversion volume. Avoid brand campaigns for the first test.
- Set the split between control and treatment. A 50/50 split gives the fastest clear answer.
- Under asset optimization, decide whether to keep text customization and final URL expansion on. For a cautious first test, many advertisers keep only search term matching.
- Add brand exclusions if you do not want competitor or your own brand searches in the test. Brand controls apply to both arms.
- Set dates and choose whether to auto apply the result. I prefer to review it manually.
Search term matching can be turned off for specific ad groups, and URL inclusions are set at ad group level. Google’s help page notes that some ad group changes are made after setup by editing the campaign. That lets you protect ad groups where precise wording or compliance matters.
When AI Max experiments are not available
The standard experiment flow does not work if the campaign:
- Already has text customization on
- Targets the Display Network
- Uses a portfolio bid strategy or a shared budget
- Uses bidding exploration
- Already has an active experiment
Fix these first, or choose another campaign.
Use the new search terms and ad combinations report
In October, a new report started appearing in some accounts. It shows, in one view, the search term, the headline and description shown, the landing page, the match source (AI Max expansion or your URL inclusions), and whether the assets were yours or generated. Rollout is limited, so you may not see it yet.
When you have it, check three things every week:
- High spend search terms that do not match what you sell. Add them as negatives. My negative keywords guide explains how.
- Generated text that overpromises. For example, a cheap service search showing an ad for your most expensive package.
- Landing pages that should never get paid traffic, such as blog posts or careers pages. Exclude them.
How to judge the result
- Run the test for at least four weeks, longer if the campaign has fewer than 30 conversions a month.
- Compare cost per conversion and conversion value, not click through rate.
- Check lead quality in your CRM. AI Max can bring more form fills that never buy.
- Look at the share of conversions that came from new search terms. That is the real value AI Max adds.
If the treatment arm wins on cost per sale or qualified lead, apply it. If it brings more volume at a higher cost, decide whether that extra volume is worth it for your margins.
Who should wait
- Accounts with broken or weak conversion tracking. Fix tracking first with my GA4 and GTM tracking guide.
- Regulated industries where every ad line must be approved.
- Very small budgets, where a test cannot reach a clear result.
Frequently asked questions
What is AI Max for Search?
How do I test AI Max without risking my campaign?
Can I turn off text customization in AI Max?
What is the AI Max search terms and ad combinations report?
How long should an AI Max test run?
Who can run an AI Max test for my account?
Want help testing AI Max?
I can set up the experiment, protect your best ad groups and report on real sales. See my Google Ads management service, or request a free ads audit.