How to request allocation of more RAM for an application?

Android limits the amount of RAM available to each application to ensure the stability of the entire system. This limit is called heap size.

Usually, it is not necessary to change it directly, as the system manages memory automatically. However, in rare cases, such as working with large raster images or data sets, it may be necessary to increase the heap size.

You can request a larger heap size by adding the attribute android:largeHeap="true" to the <application> tag in the AndroidManifest.xml file:

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="your.package.name">

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme"
        android:largeHeap="true"> // Request for larger memory

        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>
</manifest>

Important:

• Using android:largeHeap="true" should be justified and not abused. It can negatively affect system performance if multiple applications request large amounts of memory.
• Even with android:largeHeap="true", there is an upper limit to the allocated memory, which depends on the device and Android version.
• It is better to optimize memory usage in the application than to rely on increasing the heap size.

To programmatically get the current heap size:

long heapSize = Runtime.getRuntime().maxMemory();
long freeSize = Runtime.getRuntime().freeMemory();
long allocatedSize = Runtime.getRuntime().totalMemory();

// Convert to megabytes for convenience
long heapSizeMB = heapSize / (1024 * 1024);
long freeSizeMB = freeSize / (1024 * 1024);
long allocatedSizeMB = allocatedSize / (1024 * 1024);

Memory size information helps understand how efficiently the application uses resources and whether it is necessary to request a larger heap size.