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Contents
Google Ads API v25.2, released on 23 September 2026, adds URL options directly to Performance Max asset groups. An asset group brings together the creative material and destinations used for a particular theme. Its tracking template, custom parameters and final URL suffix can now be configured through the API. The change creates a more precise place to maintain tracking labels; it does not introduce a new attribution model. [1, 2]
Three fields with different jobs
The final URL is the destination, such as a category page for running shoes. A final URL suffix contains parameters appended to the landing-page address. A tracking template describes a tracking URL and can involve a separate measurement provider. Custom parameters supply named values used inside those settings. Treating these as interchangeable creates links that look plausible but deliver different information.
| Field | Purpose |
|---|---|
tracking_url_template |
A template for the tracking URL. |
url_custom_parameters |
Values substituted into supported URL fields. |
final_url_suffix |
Parameters attached to the landing-page URL. |
The distinction matters with parallel tracking: the visitor reaches the final destination while the tracking request can run in the background. A parameter intended for the website belongs in the landing-page configuration; its presence in a third-party tracking request alone is not evidence that the website receives it. [3]
A shop with two product themes
Consider a fictional campaign containing a running-shoes group and a hiking-boots group. Both promote the same shop, but the reporting needs to retain which theme led to a visit. A simple naming scheme uses stable, lowercase values such as running_shoes and hiking_boots. Those are editorial choices for this example, not required Google names.
Final URL:
https://example.com/shoes?collection=autumn
Final URL suffix:
utm_source=google&utm_medium=cpc&utm_campaign=autumn_pmax&utm_content=running_shoes
Expected landing URL in this static example:
https://example.com/shoes?collection=autumn&utm_source=google&utm_medium=cpc&utm_campaign=autumn_pmax&utm_content=running_shoesThe suffix contains neither the domain nor a leading question mark. The existing collection filter remains in place. The second asset group can use a different content label without requiring a different campaign name. A fixed label describes the group; it does not identify which individual image, headline or combination was actually shown.
What becomes easier to investigate
Separate labels make it possible to investigate whether visits associated with one product theme reach an appropriate category page, continue to product detail and complete a purchase. A report can place the label alongside the landing page and the relevant website events. This is useful for finding mismatches: hiking creative arriving on a generic shoe page, for example, or one group sending traffic through an unnecessary redirect.
Such a report still needs a defined scope. Session acquisition, an event parameter and an attributed conversion are different kinds of observation. Combining them under a column called “asset-group performance” without stating how each number was obtained obscures more than the new label reveals.
What the label does not prove
A manually assigned content value is not an experiment. More purchases after visits carrying one label do not show how many purchases the advertising caused. Different products, prices, audiences and stock levels can all affect the result. Nor does adding UTM parameters automatically produce cost data at the same level in every analytics report.
Auto-tagging and manual labels also need a deliberate relationship. Existing click identifiers should not be removed to make a URL look tidier. A tagging change is best evaluated as a change to the measurement configuration, with its date recorded, rather than as a promise that all Google Ads and analytics totals will reconcile.
A short validation sequence
First comes an inventory of the effective destination and URL settings. A blank field in an export is not sufficient evidence that no higher-level setting influences the request. Next comes a test with a destination that already has a query string, followed by one with a fragment. Duplicate keys such as two different utm_campaign values deserve attention because downstream parsers may resolve them differently.
The Google Ads URL test and an actual controlled visit then check different things: the platform validates the configuration, while the browser and the receiving analytics setup show what arrives. A local preview can expose malformed parameters, but cannot reproduce the auction, redirects or every ValueTrack substitution. Google documents both the URL insertion placeholders and their escaping rules. [4]
Keeping the change maintainable
A small dictionary of asset-group identifiers is easier to maintain than labels copied from long display names. Its owner, meaning and effective date should remain available beside the campaign configuration. Renaming an asset group need not rewrite the historical meaning of its tracking label.
The linked UTM tool provides a place to inspect the static URL components. Its result is a configuration aid, not a certificate that a campaign measures correctly. The decisive check remains the address and data observed after the visit.
Related tool
UTM Campaign Link Builder & Strict Linter
Questions and answers
Which suffix takes effect when both the campaign and the asset group carry their own final URL suffix?
For URL options, Google Ads follows the rule that the more specific level takes precedence over the more general one: a suffix at a lower level replaces the campaign suffix rather than being appended to it. If the asset group fits into this order the way an ad group does, a group suffix containing only utm_content=running_shoes displaces, within that group, the values for utm_source, utm_medium and utm_campaign from the campaign suffix.
The safer course is therefore to write each group suffix in full, as in the article’s example, and to check with a controlled visit after the change which parameters actually reach the landing page. This matches the point that a blank field in an export is not sufficient evidence that no higher-level setting applies: the order of precedence can only be read from the effective address, not from a single field.
What happens to the suffix when the landing page redirects?
That depends on the redirect. If the server rebuilds the address, for example when switching to https or appending a trailing slash, and drops the query string in the process, the UTM values are gone before any tag can read them. A controlled visit shows this in the address that finally appears in the browser.
Do the additional parameters put a strain on the page cache?
That depends on how the cache builds its keys. Many page caches and CDNs use the full address including the query string as the key. Every new combination of parameters then creates an entry of its own, and the first visit with that combination meets an uncached page. Stable group labels such as running_shoes and hiking_boots keep the number of variants small; values that change with every click, such as a click identifier from auto-tagging, turn practically every ad click into a cache miss.
Many caches can be set to leave known marketing parameters out when building the key. What matters is that the cache only disregards them for the key and does not strip them from the address with a redirect; otherwise they no longer reach the analytics setup. Server-side analysis that reads the parameters from the request also misses every visit the cache serves without passing the request on to the server.
Sources
- Google Ads API release notes, v25.2, 23 September 2026
- AssetGroup reference
- Final URL suffix
- ValueTrack parameters
Sources checked: 24 September 2026.
Checking a complete dataset
The existing UTM linter now also checks a whole campaign list from a CSV column named url. The batch report highlights missing source, medium or campaign parameters, repeated keys, spaces and campaign names that differ only in case. These are naming checks; no landing pages or redirects are fetched.
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