Google is removing one of the oldest manual controls from Search advertising: the advertiser’s campaign-level choice of target language. Effective September 30, manual language targeting is no longer supported for Search campaigns, AI Max for Search or Performance Max ads when they appear on Google Search. Instead, Google will infer the appropriate language from the ad creative, the landing page and the user’s language preferences.
The change is now listed in Google’s official Google Ads API deprecation table, which records September 30 as the effective date. Google originally announced the transition in an August 13 Google Ads Developer Blog post, describing it as a simplification of campaign management for Search, AI Max and Performance Max.
The most consequential detail is not simply that a dropdown is disappearing. Google is shifting language from an advertiser-declared eligibility setting toward an inferred matching signal. The language of the page a user will land on now participates directly in deciding which Search ad is appropriate for that user.
Search advertisers will no longer tell Google which languages to target
Until now, Google Ads has allowed advertisers to attach language criteria to campaigns. Through the API, that control is represented by CampaignCriterion.language. Advertisers could use it to specify the languages they wanted a Search campaign to target.
From September 30, that criterion is no longer used for Search or AI Max for Search. Google says existing campaigns will continue operating, but their campaign-level language settings will not apply. Existing language criteria may still be returned when queried through the API even though they no longer control Search targeting.
Google advises developers to stop including language criteria when creating or updating Search campaigns. Existing criteria can optionally be removed for cleanliness, but Google says removal is not required because the values are no longer applied to Search delivery.
The API turns the deprecation into an enforceable boundary
This is not merely a user-interface simplification. Attempts to add or update CampaignCriterion.language for a Search campaign through the Google Ads API will fail with ContextError.OPERATION_NOT_PERMITTED_FOR_CONTEXT.
That matters for agencies, bid-management platforms and internal campaign-generation systems that still treat language as a required campaign field. Their workflows need to stop sending the criterion rather than simply hiding it from a settings screen.
The API behavior also makes Google’s direction unambiguous. Language targeting is not being quietly deprioritized while remaining available to sophisticated advertisers. For Search, the manual criterion is being removed from the supported campaign-control surface.
Landing-page language becomes part of ad matching
Google tells advertisers to focus instead on the language of their ads and landing pages. Search ads will primarily use those signals alongside user language preferences to determine matching. The deprecation table likewise states that ads will automatically match users based on the language of ad creatives and landing pages.
This gives the destination page a larger role before the click occurs. The landing page has always mattered for post-click experience, policy compliance and conversion performance, but Google is now explicitly identifying its language as a signal used in the Search ad-matching process.
For multilingual advertisers, that increases the importance of keeping creative and destination language aligned. A campaign architecture that sends several languages to one ambiguous or poorly localized page is no longer protected by a separate campaign setting that explicitly declares the intended audience language.
The shift also reinforces a trend NetContentSEO has been tracking across AI-driven advertising platforms: the landing page is becoming machine-readable campaign input rather than merely the URL at the end of the ad. OpenAI, for example, now uses landing-page content in relevance and creative workflows, as we examined in our analysis of ChatGPT Ads landing-page signals.
User language preference remains part of the decision
Automatic matching does not mean Google simply reads the landing page and serves the ad to everyone who understands that language. Google says user language preferences remain a signal alongside ad and landing-page language.
The practical model is therefore contextual rather than a one-for-one replacement of the old setting. Advertisers no longer provide the explicit campaign criterion, while Google combines information from the creative, destination and user to decide which language is relevant.
When multiple eligible campaigns exist in the same account, Google says AI-based ad-group prioritization will select the most relevant ad language. That moves another decision previously influenced by campaign structure into an automated selection layer.
Performance Max keeps language targeting outside Search
The Performance Max implementation requires an important qualification. Campaign-level language targeting is not disappearing from Performance Max everywhere. Google says the setting will stop being used when Performance Max ads appear on Google Search, where language matching will behave like Search campaigns.
On other Performance Max channels—including YouTube, Display, Discover and Gmail—the advertiser’s campaign-level language selection continues to guide who sees the ads. This is why attempts to set the language criterion on Performance Max do not produce the same API error as Search campaigns: the setting still has a supported function outside Search.
For cross-channel automation systems, that means language can no longer be treated as a uniform campaign property with identical semantics everywhere. The same Performance Max setting can remain relevant to non-Search inventory while being ignored for Search delivery.
AI Max is losing another legacy campaign boundary
The timing is particularly notable for AI Max. During September, Google is also migrating Search campaigns that use campaign-level Broad Match or standalone Automatically Created Assets into AI Max configurations. The company has been progressively replacing older Search controls with automated systems that use broader sets of signals to decide matching, creative and destination behavior.
Language targeting now follows that pattern. Instead of requiring the advertiser to predefine a linguistic audience at campaign level, Google can infer language compatibility from the materials it already has and the context of the user.
That does not mean campaign structure becomes irrelevant. Advertisers still control budgets, assets, landing pages and many other inputs. But the boundary between “eligible because the advertiser selected this setting” and “eligible because Google inferred relevance from campaign content” continues to move toward the latter.
NetContentSEO recently covered another side of that transition in Google’s expansion of AI Max controls and query-to-landing-page reporting. The combination is revealing: Google is automating more of the matching decision while simultaneously promising advertisers more visibility into the path its automation ultimately chose.
Multilingual landing-page architecture becomes a paid-search input
For international advertisers, the change raises practical questions that extend beyond API migration. If landing-page language participates in matching, localization quality and URL architecture become more directly connected to paid-search delivery.
A site with clearly separated English, French, German and Spanish destinations gives Google explicit page-level evidence about which experience belongs to which language. A site that mixes languages on one page, relies heavily on client-side translation or sends multiple localized ads to a generic-language destination may provide less clean matching signals.
Google has not published a weighting formula for creative language, landing-page language and user preference, so advertisers should not infer that one signal always overrides another. Nor has Google said that a particular localization architecture is required. The documented change is narrower: those signals replace the manual Search language criterion as the basis for automatic matching.
That distinction matters because the new system should be tested rather than reverse-engineered from assumptions. Advertisers can compare search terms, geography, destination URLs, conversion quality and language-specific creative performance after the transition to identify where automated matching differs from their previous campaign boundaries.
The deprecation changes how campaign builders should validate configuration
Software that creates Search campaigns will need a simple but important validation change. A language criterion that was previously legitimate now causes a context error when an integration tries to add or modify it. Systems that clone old campaigns, generate campaigns from templates or synchronize settings across accounts are especially likely to carry the deprecated field forward unintentionally.
The safest migration is the one Google explicitly recommends: stop setting language criteria on new and updated Search campaigns. Existing values do not need to be deleted solely to keep campaigns serving, because they are ignored for Search targeting.
Reporting systems may also need to distinguish stored configuration from active behavior. Because Google says historical language criteria can continue to appear in query responses, an integration that merely reads the field could incorrectly assume it still affects eligibility.
Advertisers are trading a manual exclusion boundary for inferred relevance
The strategic trade-off is straightforward. Manual language targeting offered an explicit campaign-level boundary. Automated language matching can potentially reduce configuration overhead and handle multilingual behavior more flexibly, but advertisers no longer express that boundary through the Search campaign language setting.
Google frames the change as simplifying management while maintaining a high-quality ad experience. The company has not published evidence in the deprecation notice showing how the new system changes reach, conversion rates or linguistic mismatches relative to manual targeting, so those outcomes remain something advertisers will need to observe in their own accounts.
The architecture itself is clear, however. Search language eligibility is becoming a model-driven interpretation of campaign content and user signals rather than a manually declared criterion.
The landing page is moving upstream in AI advertising
The broader significance is that landing pages are increasingly being read before an ad is selected, not merely evaluated after the click. Search systems can use them to understand what an advertiser offers, AI systems can use them to select destinations or generate assets, and now Google explicitly says landing-page language helps determine linguistic matching for Search ads.
That changes the role of on-site content in paid acquisition. A localized page is no longer only a conversion-rate optimization asset. Its language becomes part of the information Google uses to decide whether the associated advertising experience belongs in front of a particular user.
From September 30, advertisers cannot restore the old boundary by sending CampaignCriterion.language through the API; Google will reject the operation for Search. The replacement is not another manual control. It is the combination of what the ad says, what the landing page says and what Google understands about the user.
For AI Max and the wider direction of Search advertising, that is the important shift: campaign settings are giving way to interpreted signals, and the website itself is becoming part of the targeting system.