Android Compatibility

Android's purpose is to establish an open platform for developers to build innovative mobile apps. Three key components work together to realize this platform.
The Android Compatibility Program defines the technical details of Android platform and provides tools used by OEMs to ensure that developers' apps run on a variety of devices. The Android SDK provides built-in tools that Developers use to clearly state the device features their apps require. And Google Play shows apps only to those devices that can properly run them.
These pages describe the Android Compatibility Program and how to get access to compatibility information and tools.

Why build compatible Android devices?

Users want a customizable device.

A mobile phone is a highly personal, always-on, always-present gateway to the Internet. We haven't met a user yet who didn't want to customize it by extending its functionality. That's why Android was designed as a robust platform for running after-market applications.

Developers outnumber us all.

No device manufacturer can hope to write all the software that a person could conceivably need. We need third-party developers to write the apps users want, so the Android Open Source Project aims to make it as easy and open as possible for developers to build apps.

Everyone needs a common ecosystem.

Every line of code developers write to work around a particular phone's bug is a line of code that didn't add a new feature. The more compatible phones there are, the more apps there will be. By building a fully compatible Android device, you benefit from the huge pool of apps written for Android, while increasing the incentive for developers to build more of those apps.

Android compatibility is free, and it's easy.

If you are building a mobile device, you can follow these steps to make sure your device is compatible with Android. For more details about the Android compatibility program in general, see the program overview.
Building a compatible device is a three-step process:

1. Obtain the Android software source code. This is the source code for the Android platform, that you port to your hardware.
   
2. Comply with Android Compatibility Definition Document (CDD). The CDD enumerates the software and hardware requirements of a compatible Android device.
   
3. Pass the Compatibility Test Suite (CTS). You can use the CTS (included in the Android source code) as an ongoing aid to compatibility during the development process.