Google is already testing Wear OS 5.1, could be based on Android 15

We’re merely days away from the expected unveiling of the Google Pixel Watch 3 series, and because of leaks, many details about the watches have already been made public. We already know that, for example, both watches will come with the latest version of Wear OS, Google’s Android-based platform for wearables. But ahead of its launch, Android Authority has learned that the next version of Wear OS is not only already in the works but that it could be based on a different version of Android.

Although Wear OS is based on the same open source codebase as Android for handhelds — that is, AOSP — it doesn’t follow the same release cadence or versioning. For example, Wear OS 3 was announced in May of 2021, a full eight months after the Android version it’s based on, Android 11, was released. Wear OS 4 was announced two years later, in May of 2023; it’s based on Android 13, which was released the year prior. The latest version of Wear OS announced this year, Wear OS 5, is similarly based on a version of Android that was actually released last year — Android 14.

It gets even more confusing when you discuss Wear OS skins, like Samsung’s One UI Watch. In the screenshot below, you can see that the Samsung Galaxy Watch Ultra runs One UI 6.0 Watch, which is based on Wear OS 5.0, which is itself based on Android 14.

There’s been no real trend or consistency to the Wear OS release schedule so far, though some believe that Google is now on a yearly release cycle, given the release dates of the last two versions. However, Wear OS, like Android for handhelds, also sometimes sees interim “point” updates that add new features but not new APIs. The last Wear OS point update was Wear OS 3.5, released in early 2022; Google never pushed a point update for Wear OS 4, instead skipping straight to Wear OS 5. Google might be back to releasing Wear OS point updates, though, as an insider shared with Android Authority that Google is testing Wear OS 5.1 out on the Pixel Watch 2.

The existence of Wear OS 5.1 is hardly newsworthy in and of itself, especially since we, unfortunately, don’t know what new features Google has planned for it. However, when we learned that Google’s Wear OS 5.1 test builds were based on Android 15 rather than Android 14, we were intrigued. If Wear OS 5.0 is based on Android 14 whereas Wear OS 5.1 is based on Android 15, then that means that Google has finally fully decoupled the underlying Android version from the Wear OS version.

This is actually something that Google has been working towards for a while now. Google’s “trunk stable” project has resulted in a single main development branch for all of Android; the exact apps, APIs, features, and behaviors found in an Android build are now not only determined by when the build was compiled but also by what build flags and Android config (aconfig) flags were enabled.

Of course, I’m oversimplifying things quite a bit, but our insider revealed some information that backs up what we’re saying. While Wear OS 5.0 test builds have build IDs that start with AW2A, current Wear OS 5.1 test builds have build IDs that start with AP4A, which is in line with how regular Android builds are identified post-trunk stable. It’s possible that Wear OS 5.1 is just a temporary name, though, which means it could be bumped to “Wear OS 6″ prior to release. That would depend on whether or not Google plans to include any new APIs or app-facing system behaviors, as those are when Google tends to bump the Wear OS major version.