AI Max vs Performance Max: Which One, When, and What the Migration Changes

AI Max is a setting. Performance Max is a campaign type. That one line resolves most of the confusion, because the two are not alternatives to each other in the way the query implies. AI Max is a suite of features you switch on inside an existing Search campaign, so it only ever serves on Search, and you keep your keywords, your ad groups and your negative keywords (Google Ads Help, checked 3 September 2026). Performance Max is a separate campaign you create, which serves across Search, Shopping, YouTube, Display, Discover, Gmail and Maps from one asset pool, and has no keywords at all.

So the practical decision is not "which one". If you run Search campaigns, AI Max is now a default you have to actively manage: since 1 September 2026 Google has been auto-migrating Search campaigns that used campaign-level broad match or standalone automatically created assets, and new Search campaigns are created with AI Max on (Search Engine Land, 14 August 2026). Performance Max stays a separate question about whether you want a cross-channel campaign at all.

What AI Max actually is

Google's help documentation describes AI Max as "a comprehensive suite of targeting and creative features that leverages AI for Google Ads to optimize your ads in real time." It sits on top of a Search campaign. Three features do the work:

• Search term matching. Expands reach using broad match plus keywordless technology, matching on your ads, landing pages and context rather than only your keyword list. Toggled at campaign level, and can be switched off per ad group.
• Text customization. Generates and tests extra headlines and descriptions from your existing assets and website content, then picks combinations at auction time. This is the feature formerly called automatically created assets.
• Final URL expansion. Sends the click to whichever page on your domain Google predicts fits the query best, rather than the URL you set.

Text customization and final URL expansion both turn on by default when AI Max is enabled, and both live in the Asset optimization panel under Settings (Google Ads Help: set up AI Max). They are chained: turning text customization off also turns final URL expansion off.

Two dependencies matter before you touch anything. Search term matching does not work on manual CPC, so AI Max effectively requires a conversion-based Smart Bidding strategy (Google Ads Help FAQ). And when text customization and final URL expansion are both on, RSA asset pinning is no longer respected, per the same FAQ. If you pin for compliance reasons, that is a hard stop.

What Performance Max actually is

Performance Max is a campaign type. You supply assets, a feed if you have one, budget, a conversion goal and audience signals, and Google decides the channel mix. There are no keywords to write and no ad groups in the Search sense, only asset groups.

The old complaint that PMax is a black box is out of date. As of September 2026 it carries campaign-level negative keywords, brand exclusions, channel performance reporting, first-party data exclusions, demographic exclusions, and since 30 April 2026 explicit toggles for the Search Partner Network and the Google Display Network (PPC News Feed, 30 April 2026). Channel diagnostics arrived on 1 July 2026 under Insights and reports, showing per-channel status and which missing assets block eligibility (PPC News Feed, 1 July 2026).

What PMax still does not give you is query-level intent control. You cannot say "bid on this phrase and nothing near it". That is the whole reason Search campaigns survive.

What AI Max changes inside a Search campaign

Three things change on the day it turns on, and each has a different failure mode.

Matching gets looser. Keywordless recall means the campaign can serve on queries with no relationship to any keyword you wrote. In our writeup of a one week on, one week off test on a single campaign, the account manager reported 955 distinct search terms in the week AI Max was on and 30 in the week after he switched it off, with nothing else changed. That is his number from one campaign, not a benchmark, but it is the shape of the change.

Ad copy stops being exactly what you wrote. Text customization writes from your landing pages. Brad Geddes tested it across three companies spending at least $20,000 a month with 100 or more ad groups, and reported roughly 19 percent of auto-generated assets had to be removed, and that the B2B lead gen account abandoned the test after three weeks because click-through rate rose while conversion rate fell as the ads pulled in B2C searchers (Search Engine Land, 28 July 2026).

Landing pages stop being fixed. Final URL expansion can route a click to any page on your domain. Your blog, your careers page and every legacy product page are in scope until you add URL exclusions.

There is also a migration trap. Google's documentation now says broad keywords are not treated as exact match keywords in prioritization when you move to AI Max, and that keeping your previous prioritization means adding copies of your exact match keywords, which loses the historical statistics on them (Search Engine Roundtable, 1 September 2026). Read that twice before you bulk-add anything.

The controls you keep, and the ones you lose

You keep negative keywords, and the FAQ confirms AI Max respects them. You keep brand inclusions and exclusions, URL inclusions and exclusions, and locations of interest at ad group level. Reported limits as of 1 September 2026: 10 brand inclusion lists and 10 brand exclusion lists of up to 5,000 brands each, 25 term exclusions, 40 message constraints, and a practical floor of 15 to 30 conversions in 30 days for search term matching (Search Engine Land, 1 September 2026). Treat those as reported figures and check them in your own account.

Where each toggle lives, per Google's setup documentation:

What you lose is pinning, when both asset optimization features are on, and the ability to predict which page a click lands on until you scope it.