Behavior changes: Apps targeting Android 17 or higher

Like previous releases, Android 17 includes behavior changes that might affect your app. The following behavior changes apply exclusively to apps that are targeting Android 17 or higher. If your app is targeting Android 17 or higher, you should modify your app to support these behaviors, where applicable.

Be sure to also review the list of behavior changes that affect all apps running on Android 17 regardless of your app's targetSdkVersion.

Note: This page lists some of the more important changes. For more detailed information, see the Android 17 release notes.

Core functionality

Android 17 includes the following changes that modify or expand various core capabilities of the Android system.

New lock-free implementation of MessageQueue

Beginning with Android 17, apps targeting Android 17 or higher receive a new lock-free implementation of android.os.MessageQueue. The new implementation improves performance and reduces missed frames, but may break clients that reflect on MessageQueue private fields and methods.

For more information, including mitigation strategies, see MessageQueue behavior change guidance.

Static final fields are now unmodifiable

Apps running on Android 17 or higher that target Android 17 or higher cannot change static final fields. If an app attempts to change a static final field by using reflection, it will cause an IllegalAccessException. Attempting to modify one of these fields through JNI APIs (such as SetStaticLongField()) will cause the app to crash.

Accessibility

Android 17 makes the following changes to improve accessibility.

Accessibility support of complex IME physical keyboard typing

This feature introduces new AccessibilityEvent and TextAttribute APIs to enhance screen reader spoken feedback for CJKV language input. CJKV IME apps can now signal whether a text conversion candidate has been selected during text composition. Apps with edit fields can specify text change types when sending text changed accessibility events. For example, apps can specify that a text change occurred during text composition, or that a text change resulted from a commit. Doing this enables accessibility services such as screen readers to deliver more precise feedback based on the nature of the text modification.

App adoption

• IME Apps: When setting composing text in edit fields, IMEs can use TextAttribute.Builder.setTextSuggestionSelected() to indicate whether a specific conversion candidate was selected.

• Apps with Edit Fields: Apps that maintain a custom InputConnection can retrieve candidate selection data by calling TextAttribute.isTextSuggestionSelected(). These apps should then call AccessibilityEvent.setTextChangeTypes() when dispatching TYPE_VIEW_TEXT_CHANGED events. Apps targeting Android 17 that use the standard TextView will have this feature enabled by default. (That is, TextView will handle retrieving data from the IME and setting text change types when sending events to accessibility services).

• Accessibility Services: Accessibility services that process TYPE_VIEW_TEXT_CHANGED events can call AccessibilityEvent.getTextChangeTypes() to identify the nature of the modification and adjust their feedback strategies accordingly.

Privacy

Android 17 includes the following changes to improve user privacy.

Local network permission required for apps targeting Android 17

Available to test? (Required build)	Yes (Android 17 or later)
Requires changing targetSDKVersion? (API level)	Yes (API Level "CINNAMON_BUN") See the manifest attribute documentation for more information about this value.

Content included from the public site
The following documentation mirrors the public Android 17 site on developer.android.com and is provided here for your convenience.

Android 17 introduces the ACCESS_LOCAL_NETWORK runtime permission to protect users from unauthorized local network access. Because this falls under the existing NEARBY_DEVICES permission group, users who have already granted other NEARBY_DEVICES permissions aren't prompted again. This new requirement prevents malicious apps from exploiting unrestricted local network access for covert user tracking and fingerprinting. By declaring and requesting this permission, your app can discover and connect to devices on the local area network (LAN), such as smart home devices or casting receivers.

Apps targeting Android 17 or higher now have two paths to maintain communication with LAN devices: Adopt system-mediated, privacy-preserving device pickers to skip the permission prompt, or explicitly request this new permission at runtime to maintain local network communication.

For more information, see the Local network permission documentation.

Note: In Android 16, apps could opt in to local network permissions. Beginning with Android 17, enforcement is mandatory for apps that target Android 17 or higher.

Security

Android 17 makes the following improvements to device and app security.

Activity Security

In Android 17, the platform continues its shift toward a "secure-by-default" architecture, introducing a suite of enhancements designed to mitigate high-severity exploits such as phishing, interaction hijacking, and confused deputy attacks. This update requires developers to explicitly opt in to new security standards to maintain app compatibility and user protection.

Key impacts for developers include:

• BAL hardening & improved opt-in: We are refining Background Activity Launch (BAL) restrictions by extending protections to IntentSender. Developers must migrate away from the legacy MODE_BACKGROUND_ACTIVITY_START_ALLOWED constant. Instead, you should adopt granular controls like MODE_BACKGROUND_ACTIVITY_START_ALLOW_IF_VISIBLE, which restricts activity starts to scenarios where the calling app is visible, significantly reducing the attack surface.
• Adoption tools: Developers should utilize strict mode and updated lint checks to identify legacy patterns and ensure readiness for future target SDK requirements.

Enable CT by default

If an app targets Android 17 or higher, certificate transparency (CT) is enabled by default. (On Android 16, CT is available but apps had to opt in.)

Safer Native DCL—C

If your app targets Android 17 or higher, the Safer Dynamic Code Loading (DCL) protection introduced in Android 14 for DEX and JAR files now extends to native libraries.

All native files loaded using System.load() must be marked as read-only. Otherwise, the system throws UnsatisfiedLinkError.

We recommend that apps avoid dynamically loading code whenever possible, as doing so greatly increases the risk that an app can be compromised by code injection or code tampering.

Device form factors

Android 17 includes the following changes to improve user experience across a range of device sizes and form factors.

Platform API changes to ignore orientation, resizability and aspect ratio constraints on large screens (sw>=600dp)

We introduced Platform API changes in Android 16 to ignore orientation, aspect ratio, and resizability restrictions on large screens (sw >= 600dp) for apps targeting API level 36 or higher. Developers have the option to opt out of these changes with SDK 36, but this opt-out will no longer be available for apps that target Android 17 or higher.

For more information, see Restrictions on orientation and resizability are ignored.