Google has announced a major change for developers looking to list their apps on Google Play that could have an impact on the Android app ecosystem. Now, the default format for app publishing is the APK, but from August Google requires that new Play apps are published using the Android App Bundle instead.

On a Google page about Android App Bundle, the company touts many potential improvements with the new format, such as smaller app downloads for users. But the format has a catch: Android App Bundles are a format that only Google Play uses, which could complicate the redistribution of apps.

The App Bundles requirement only applies to new apps

The timing of Google’s announcement also comes just days after Microsoft announced Windows 11, which lets you sideload Android apps as APKs. Google’s move to App Bundles may mean fewer apps will be available to run on Microsoft’s new operating system, although you can also get Android apps on Windows 11 from the Amazon Appstore.

According to Google, the requirement to use Android App Bundles only applies to new apps. “Existing apps are currently exempt, as are private apps published to managed Google Play users,” the company says. And if you’re a developer planning to release a new app, you’ll only have a short amount of time to make sure you’re using the new format.