Google on July 6, 2026 designated its rewritten Google Mobile Ads Next-Gen SDK as the preferred software development kit for Android, a decision that simultaneously classifies the SDK that had powered in-app advertising integrations for years as legacy technology. The announcement, posted to the Google Ads Developer Blog by Natalia Vargas-Caba of Mobile Ads Developer Relations, applies to developers building for both Google AdMob and Google Ad Manager.

The change is more than a naming update. It starts a formal deprecation clock for the older SDK, one that Google says mirrors the retirement schedules it has applied to previous major SDK versions. According to the announcement, GMA Next-Gen SDK represents a significant rewrite of the Google Mobile Ads SDK, built to improve speed, stability, and the day-to-day experience of building against it. Google frames the older codebase, by contrast, as something developers should now plan to leave behind.

What the deprecation schedule actually requires

The blog post lays out a three-stage timeline that governs how long apps built on Google Mobile Ads SDK (legacy) version 25.x.x can keep functioning. Each stage carries a distinct technical consequence, and the gap between them gives development teams a fixed, published runway rather than an open-ended warning.

The first stage, labeled supported, runs through July 1, 2026. During this period, ads continue to serve normally, and Google still provides technical support for developers who run into integration problems, reachable through a dedicated contact form.

The second stage, labeled deprecated, begins June 30, 2027. Ads still serve during this phase. What disappears is technical support: developers troubleshooting issues with the legacy SDK after that date will not have a Google support channel to turn to, even though their apps keep running.

The third and final stage, labeled sunset, arrives June 30, 2028. According to the announcement, ads are at risk of not serving once an app reaches this stage, and the legacy SDK becomes reported as outdated, which then prevents further app releases. That last detail matters as much as the ad-serving risk itself. A developer who has not migrated by the sunset date may find they cannot ship updates to their own app at all, since the outdated SDK designation blocks new releases through app store review processes that check for current, supported dependencies.

Google states that version 25.x.x follows a similar deprecation schedule, as previous major versions, positioning this timeline as consistent with how the company has retired SDK generations before, rather than as an unusually aggressive cutoff. Developers wanting the full technical definitions behind each stage - supported, deprecated, and sunset - can consult Google's published deprecation schedule, which the blog post links directly.

Migration tools built for both manual and AI-assisted workflows

Google is pairing the deprecation timeline with migration resources aimed at two different kinds of developers: those who prefer traditional documentation, and those increasingly working through AI coding agents.

For manual migration, Google points developers to a Set up GMA Next-Gen SDK guide covering the latest version and setup instructions for both AdMob and Ad Manager integrations, alongside a separate migration guide with direct instructions for moving from the legacy SDK to GMA Next-Gen SDK. Developer samples are also available through a GitHub repository named gma-next-gen-sdk-android-examples, which Google says contains example applications developers can reference during their own integration work.

The second migration path reflects a broader shift inside Google's advertising developer tooling. According to the announcement, Google recently introduced agent skills, and one of those skills - named google-mobile-ads-android-migrate-to-next-gen - is built specifically to help developers migrate an app from the legacy SDK to GMA Next-Gen SDK using AI coding tools. Google directs developers seeking detail on this approach to a page titled Migrate with AI tools.

This is not an isolated experiment. Google's own developer relations team has discussed AI-assisted SDK migration in other public settings this year. During the third episode of the company's Ads DevCast podcast series, Developer Relations Engineer Matt Landers introduced what he described as a skill - a context file that can be loaded into a coding agent - designed to help developers migrate between AdMob SDK versions, explicitly noting that the skill was not restricted to any single AI platform and could be referenced by any coding agent. Landers, in the same episode, described going more than six months without writing a line of code by hand, framing domain knowledge as still essential for knowing what to ask an AI tool to do, even as the tool increasingly handles the syntax itself.

For developers who need direct help beyond self-service guides, Google also points to its SDK support contact channel, and to a GMA Next-Gen SDK channel on the company's Discord server, where the announcement invites developers to discuss the migration and share feedback with Google's team directly.

How the new SDK compares to what came before

While the July 6 announcement centers on the deprecation timeline rather than on introducing new performance figures, the shift builds directly on a beta release Google shipped earlier this year. Google released the Google Mobile Ads Next-Gen SDK in beta on January 22, positioning the rewrite as the company's most significant mobile advertising infrastructure update since the original SDK's launch.

At that stage, Google published specific performance benchmarks: banner ad requests completing up to 27 percent faster than the previous version, alongside a 17 percent reduction in the SDK's device footprint. Early adopters reported results beyond those published figures during the beta period. One digital media developer, cited in a Google announcement video from that time, saw a 36 percent increase in eCPM compared to the previous SDK across a three-week testing window, nearly doubling average revenue per daily active user in the process. A separate developer reported a 16 percent increase in ad fill rate, while a mobile game developer recorded a one-third reduction in Application Not Responding rates and a 50 percent cut in slow cold starts.

The beta also introduced the initialization requirement that remains central to how the SDK operates: developers must call the SDK's initialization method on a background thread before loading ads or interacting with other SDK functions, a change from the optional initialization approach the legacy SDK allowed. Google has stated that skipping background-thread initialization risks triggering Application Not Responding errors, a common source of negative user reviews and uninstalls in mobile app ecosystems.

Since the January beta, Google has kept the SDK on what the company earlier described as a monthly release cadence, a pattern that mirrors the release schedule Google separately adopted for the Google Ads API beginning in January 2026. The July 6 announcement does not restate the specific performance percentages published during the beta, focusing instead on the deprecation mechanics that now formalize the transition away from the legacy SDK entirely.

Why this matters beyond a single SDK version

The mobile advertising ecosystem depends heavily on SDK-level integration between app developers and ad networks; any disruption at that layer of the stack has downstream consequences for how ads render, how quickly they load, and ultimately how much revenue an app generates. A slower or less stable ad SDK does not just create a technical inconvenience for developers - it can measurably affect the user experience within an app and the monetization outcomes publishers depend on. That connection between SDK performance and business results is precisely why Google's published beta figures - the latency reduction, the footprint cut, the fill rate gains reported by early testers - carry weight for publishers deciding when to prioritize migration work.

Deprecation announcements of this kind also arrive against a backdrop of broader pressure on the open web's advertising infrastructure. Alphabet's own Q1 2026 earnings disclosure showed that Google Network revenue - the segment spanning AdSense, AdMob, and Ad Manager combined - declined 4 percent year-over-year to $6.97 billion, even as the company's consolidated revenue climbed. Mobile app publishers monetizing through AdMob sit inside that same Network segment, meaning SDK-level performance improvements are one of the few tools publishers have to defend revenue per impression even as broader traffic and platform dynamics work against them.

Google has also had a difficult recent stretch operationally on the advertising infrastructure side. In mid-January 2026, Google Ad Manager and AdSense experienced a two-day technical incident in which publishers reported eCPM declines ranging from 50 percent to 90 percent, driven by a systemic decline in Ad Exchange match rates and delivery. That episode, unrelated to the Mobile Ads SDK directly, nonetheless illustrated how dependent publisher revenue is on the stability of Google's underlying ad-serving infrastructure - a dependency that makes a stability-focused SDK rewrite more consequential than it might otherwise appear.

There is also a pattern worth noting in how Google has begun pairing infrastructure deprecations with AI-assisted migration tooling rather than documentation alone. The agent skill referenced in the July 6 announcement follows a similar approach Google took with a separate, unrelated SDK-level change in May 2026, when the company introduced TFAT, a new age-treatment signal replacing the older TFCD and TFUA settings across the Google Publisher Tag, GMA SDK, and IMA SDK. That announcement, too, required publishers and developers to migrate away from legacy tags within their existing SDK integrations, though Google did not specify a hard cutoff date for that particular change at the time. Taken together, these episodes suggest Google now treats coding-agent-compatible migration guides as a standard companion to deprecation announcements, not an occasional extra.

What developers face in practical terms

For a development team managing an Android app monetized through AdMob or Ad Manager, the July 6 announcement translates into a concrete decision point rather than an abstract policy shift. Apps currently running Google Mobile Ads SDK (legacy) version 25.x.x will continue serving ads without interruption through July 1, 2026, and indeed through the entirety of the deprecated phase that follows. The practical risk window opens at the sunset date, June 30, 2028, when ad serving itself becomes uncertain and, separately, the SDK's outdated status prevents further app releases.

That two-year gap between the deprecated and sunset stages gives teams meaningful lead time, but the loss of technical support at the deprecated stage - beginning June 30, 2027 - means any integration problems discovered after that point will need to be resolved without direct Google assistance, whether through community channels like the GMA Next-Gen SDK Discord server, independent troubleshooting, or migration to the newer SDK regardless of remaining runway.

Because the legacy SDK supports the full range of ad formats also available in GMA Next-Gen SDK - banner, interstitial, rewarded, rewarded interstitial, native, and app open ads - developers are not migrating to gain access to new ad inventory types. The migration is instead a performance, stability, and long-term support decision, one where the earlier a team moves, the longer it retains access to Google's direct technical support during the transition.

Timeline

  • January 10, 2025: Google publishes GMA Next-Gen SDK documentation outlining initialization requirements and technical specifications.
  • January 22, 2026: Google releases the Google Mobile Ads Next-Gen SDK for Android in beta, publishing benchmarks of a 27 percent reduction in banner ad latency and a 17 percent cut in device footprint.
  • July 1, 2026: The Google Mobile Ads SDK (legacy) enters the supported stage of its deprecation schedule; ads continue serving and technical support remains available.
  • July 6, 2026: Google designates GMA Next-Gen SDK as the preferred SDK for Android development with AdMob and Ad Manager, formally classifying the previous SDK as legacy.
  • June 30, 2027: The legacy SDK moves into the deprecated stage; ads continue serving, but Google technical support ends.
  • June 30, 2028: The legacy SDK reaches its sunset stage; ads are at risk of not serving, and the SDK's outdated status prevents further app releases.

Summary

Who: Google's Mobile Ads Developer Relations team, represented in the announcement by Natalia Vargas-Caba, addressing Android app developers who integrate advertising through Google AdMob and Google Ad Manager.

What: Google designated the Google Mobile Ads Next-Gen SDK as the preferred SDK for Android development, formally classifying the previous Google Mobile Ads SDK as legacy and subject to a three-stage deprecation schedule running through a June 30, 2028 sunset date.

When: The announcement was published July 6, 2026, with the deprecation schedule's first stage beginning July 1, 2026, its second stage beginning June 30, 2027, and its final sunset stage set for June 30, 2028.

Where: The change applies to Android app developers globally who integrate the Google Mobile Ads SDK for monetization through AdMob or Ad Manager, with migration resources available through Google's developer documentation, a GitHub sample repository, and a dedicated Discord channel.

Why: Google positions the shift as a stability and performance upgrade following a January 2026 beta that demonstrated measurable latency and footprint improvements, while the formal deprecation schedule creates a defined incentive structure - support ending in 2027, ad serving and app releases put at risk in 2028 - for developers to complete migration within a fixed window.