Figure 1. An application running in compatibility mode on an Android 3.2 tablet.

Figure 2. The same application from figure 1, with compatibility mode disabled.

Notice: If you've developed an application for a version of Android lower than Android 3.0, but it does resize properly for larger screens such as tablets, you should disable screen compatibility mode in order to maintain the best user experience. To learn how to quickly disable the user option, jump to .

Screen compatibility mode is an escape hatch for applications that are not properly designed to resize for larger screens such as tablets. Since Android 1.6, Android has supported a variety of screen sizes and does most of the work to resize application layouts so that they properly fit each screen. However, if your application does not successfully follow the guide to Supporting Multiple Screens, then it might encounter some rendering issues on larger screens. For applications with this problem, screen compatibility mode can make the application a little more usable on larger screens.

There are two versions of screen compatibility mode with slightly different behaviors:

Version 1 (Android 1.6 - 3.1) The system draws the application's UI in a "postage stamp" window. That is, the system draws the application's layout the same as it would on a normal size handset (emulating a 320dp x 480dp screen), with a black border that fills the remaining area of the screen.

This was introduced with Android 1.6 to handle apps that were designed only for the original screen size of 320dp x 480dp. Because there are so few active devices remaining that run Android 1.5, almost all applications should be developed against Android 1.6 or greater and should not have version 1 of screen compatibility mode enabled for larger screens. This version is considered obsolete.

To disable this version of screen compatibility mode, you simply need to set android:minSdkVersion or android:targetSdkVersion to "4" or higher, or set android:resizeable to "true".

Version 2 (Android 3.2 and greater) The system draws the application's layout the same as it would on a normal size handset (approximately emulating a 320dp x 480dp screen), then scales it up to fill the screen. This essentially "zooms" in on your layout to make it bigger, which will usually cause artifacts such as blurring and pixelation in your UI.

This was introduced with Android 3.2 to further assist applications on the latest tablet devices when the applications have not yet implemented techniques for Supporting Multiple Screens.

In general, large screen devices running Android 3.2 or higher allow users to enable screen compatibility mode when the application does not explicitly declare that it supports large screens in the manifest file. When this is the case, an icon (with outward-pointing arrows) appears next to the clock in the system bar, which allows the user to toggle screen compatibility mode on and off (figure 3). An application can also explicitly declare that it does not support large screens such that screen compatibility mode is always enabled and the user cannot disable it. (How to declare your application's support for large screens is discussed in the following sections.)

Figure 3. The pop up menu to toggle screen compatibility mode (currently disabled, so normal resizing occurs).

As a developer, you have control over when your application uses screen compatibility mode. The following sections describe how you can choose to disable or enable screen compatibility mode for larger screens when running Android 3.2 or higher.

Source: developer.android.com