Mishaal Rahman / Android Authority
In brief
- With One UI 6.1.1, you no longer have to tap Launch Now every time you want to stream an app from your Galaxy device to your Windows PC via Phone Link.
- This became an issue due to a limitation in Android 14 that affected the method Link to Windows used to stream apps.
- In the latest version of One UI, the Link to Windows service has changed the way apps are streamed to your PC to bypass Android 14’s limitations.
If you have an Android phone and a Windows PC, the best way to improve collaboration between the devices is to install Link to Windows on your phone. By installing Link to Windows on your Android phone, you can access a number of its features from the Windows Phone Link app on your PC, including viewing and sending text messages, making phone calls, controlling music playback, and more. However, some features in Phone Link, such as app streaming, are only available if Link to Windows is pre-installed on your Android phone. For example, Link to Windows comes pre-installed on Galaxy phones running Samsung’s One UI software, but after the One UI 6.0 update, streaming apps from Galaxy phones to Windows PCs became a bit of a pain. Thankfully, that’s no longer the case thanks to a change in One UI 6.1.1.
After the Android 14 update rolled out to users of Android phones that supported app streaming via Link to Windows, people quickly realized that the update made streaming apps significantly more annoying.
The problem that many people were facing now was that after the Android 14 update, they had to tap the Launch Now button every time they wanted to mirror their phone’s screen or an app. Before the Android 14 update, you only had to tap the Launch Now button once per launch. This change essentially forced you to reach for your phone every time you wanted to cast another app to your PC.
Mishaal Rahman / Android Authority
The reason for this was that Android 14 closed a loophole exploited by apps like Link to Windows that allowed them to bypass user consent every time an app streamed.
More specifically, the API that Link to Windows has been using all this time – MediaProjection – was never intended for streaming apps. Instead, it is designed to record or broadcast the device screen, not to control it. Allowing an app to record the screen could be dangerous. That’s why every time an app wants to start a screen recording session via the MediaProjection API, the system prompts the user to grant the app permission. This is where the dialog with the “Start Now” button comes into play.
However, before Android 14, apps could bypass the MediaProjection consent dialog by reusing the same intent that was previously returned when calling the API. This effectively meant that they only had to ask for permission once per launch. However, Google saw this as a security issue and therefore closed this loophole in Android 14. This means that apps now have to ask for user consent every time they want to use the MediaProjection API to record or broadcast the screen. The result is better security for all users, but also a more annoying app streaming experience.
However, if you use the Chrome OS Phone Hub feature to stream apps from your Android phone to your Chromebook, you weren’t affected by this change in Android 14. That’s because the Cross-Device Services app on Android phones uses the operating system’s Companion App Streaming APIs, a set of APIs Google introduced in Android 13 that are designed for app streaming. When you try to launch an app from your phone on a Chromebook, Cross-Device Services creates a virtual display, launches the app on that display, and then streams video of that display to the Chromebook. Chrome OS then routes inputs and other data back to the virtual display.
With the release of One UI 6.1.1, currently only available on the Samsung Galaxy Z Fold 6 and Galaxy Z Flip 6, Microsoft appears to have migrated its Link to Windows service to Android’s purpose-built implementation. This eliminates the need to tap a button every time I want to stream an app from my Galaxy Z Fold 6 to my Windows PC. While my phone still needs to be unlocked to stream an app, that’s an intentional and understandable limitation Microsoft has put in place for security reasons.
Left: Shows that Link to Windows on the Galaxy Z Fold 6 now uses the same streaming method for virtual display apps as Google’s Phone Hub.
Right: Shows that the Windows Service Link app has been assigned the same App Streaming role that is assigned to cross-device services on Pixel phones.
The Galaxy Z Fold 6 and Z Flip 6 are the first devices I’ve seen to include this updated Link to Windows implementation. Other companies like ASUS have included a modification that allows you to give Link to Windows permission to record the screen until the next reboot, but that’s clearly not a good long-term solution as it explicitly bypasses the security restriction Google intentionally built into Android 14. By migrating to Android’s purpose-built implementation, Link to Windows will be able to take advantage of any future features Google may add to improve Android’s app streaming experience.
