Most Performance Max controls are about queries: negative keywords and brand exclusions decide which searches you stay out of. A quieter question is which pages the campaign is allowed to send people to. By default, Google can choose the landing page itself, and that is not always the page you would pick. URL exclusions are the control for it.
What final URL expansion does
Final URL expansion lets Performance Max replace the final URL you set with another page from your site when Google's system judges it more likely to convert for a given search, and it can also generate dynamic headlines from that page's content. It is on unless you opt out. That is useful when your site is well organized and risky when it is not: a careers page, a login screen, a printable price sheet, an out-of-stock product, or a thin tag archive can all be fair game.
Two ways to control it
The blunt option is to turn final URL expansion off for the campaign, so traffic goes only to the URLs in your asset groups (and your page feed, if you use one). Google's documentation advises against opting out in general because it can limit the ads your campaign serves, but it is the right call when a campaign must send everyone to one specific page.
The precise option is to leave expansion on and add URL exclusions, which keep named pages or URL patterns out of the pool Google can choose from.
The steps
In the Google Ads interface, open the campaign's Settings, expand the asset optimization section (labelled "Automatically created assets" in some accounts), and choose Add URL exclusions. You can exclude an exact URL, which blocks only that page, or add a URL rule such as "contains /blog", which blocks every URL containing that text. Through the API, the same exclusions are set with negative WEBPAGE campaign criteria. The wording of the menus shifts from time to time, so treat the labels here as a guide and check the current Google Ads Help article.
Which pages to exclude
- Pages that cannot convert: login, account, cart-recovery, and thank-you pages.
- Pages that send the wrong message: job listings, press pages, investor pages, and support articles.
- Pages that are thin or temporary: expired offers, discontinued products, and tag or filter archives.
- Pages that compete with a campaign you run separately, such as a brand-search Search campaign.
What exclusions will not do
Google states that the campaign's own final URL cannot be excluded with URL exclusions: if you exclude it, it will still serve and receive traffic. If your campaign uses a Merchant Center feed, your homepage may also still serve for certain inventory types, such as Shopping ads on Gmail, even when excluded. Exclusions also apply to where traffic lands, not to which queries trigger the ad, so they sit alongside your negatives and brand exclusions rather than replacing them.
Broad rules deserve care. Google warns that an overly broad rule can significantly limit the system's ability to find relevant traffic, so prefer exact URLs, or narrow patterns, over a sweeping "contains".
A short audit routine
- Run a landing page report for the campaign and sort by spend.
- Flag any page you would not have chosen, and any page that cannot convert.
- Exclude the exact URLs first; use a pattern only where a whole section is wrong.
- Log each exclusion with the date so a performance shift can be traced to it.
- Recheck the report after a few weeks, and again whenever the site is restructured.
Pair this with the query-side controls: adding negative keywords to a Performance Max campaign, excluding brand searches, and adding search themes.
Sources: Google Ads Help, "About URL exclusion in Performance Max" and "About Final URL expansion in Performance Max"; Google Ads API documentation, "Create the campaign criteria" for Performance Max.