Versioning is a critical component of your application upgrade/maintenance
- Users need to have specific information about the application version that
is installed on their devices and the upgrade versions available for
- Other applications — including other applications that you publish as
a suite — need to query the system for your application's version, to
determine compatibility and identify dependencies.
- Services through which you will publish your application(s) may also need to
query your application for its version, so that they can display the version to
users. A publishing service may also need to check the application version to
determine compatibility and establish upgrade/downgrade relationships.
The Android system itself does not ever check the application version
information for an application, such as to enforce restrictions on upgrades,
compatibility, and so on. Instead, only users or applications themselves are
responsible for enforcing any version restrictions for applications themselves.
The Android system does check any system version compatibility expressed
by an application in its manifest, in the
minSdkVersion attribute. This
allows an application to specify the minimum system API with which is compatible.
For more information see
Specifying Minimum System API Version.
Setting Application Version
To define the version information for your application, you set attributes in
the application's manifest file. Two attributes are available, and you should
always define values for both of them:
android:versionCode — An integer value that represents
the version of the application code, relative to other versions.
The value is an integer so that other applications can programatically
evaluate it, for example to check an upgrade or downgrade relationship. You can
set the value to any integer you want, however you should make sure that each
successive release of your application uses a greater value. The system does not
enforce this behavior, but increasing the value with successive releases is
Typically, you would release the first version of your application with
versionCode set to 1, then monotonically increase the value with each release,
regardless whether the release constitutes a major or minor release. This means
android:versionCode value does not necessarily have a
strong resemblence to the application release version that is visible to the
android:versionName, below). Applications and publishing
services should not display this version value to users.
android:versionName — A string value that represents the
release version of the application code, as it should be shown to users.
The value is a string so that you can describe the application version as a
<major>.<minor>.<point> string, or as any other type of
absolute or relative version identifier.
android:versionCode, the system does not use this value
for any internal purpose, other than to enable applications to display it to
users. Publishing services may also extract the
value for display to users.
You define both of these version attributes in the
<manifest> element of the manifest file.
Here's an example manifest that shows the
android:versionName attributes in the
<?xml version="1.0" encoding="utf-8"?>
<application android:icon="@drawable/icon" android:label="@string/app_name">
In this example, note that
android:versionCode value indicates
that the current .apk contains the second release of the application code, which
corresponds to a minor follow-on release, as shown by the
The Android framework provides an API to let applications query the system
for version information about your application. To obtain version information,
applications use the
method of PackageManager.
Specifying Minimum System API Version
If your application requires a specific minimum version of the Android
platform, you can specify that version as an API Level identifier
in the application's manifest file. Doing so ensures that your
application can only be installed on devices that
are running a compatible version of the Android system.
To specify the minimum system version in the manifest, use this attribute:
android:minSdkVersion — An integer value corresponding to
the code version of the Android platform.
When preparing to install an application, the system checks the value of this
attribute and compares it to the system version. If the
android:minSdkVersion value is greater than the system version, the
system aborts the installation of the application.
If you do not specify this attribute in your manifest, the system assumes
that your application is compatible with all platform versions.
To specify a minimum platform version for your application, add a
<uses-sdk> element as a child of
<manifest>, then define the
android:minSdkVersion as an attribute.
For more information, also see the Android System Image 1.1 Version Notes.