Android’s split-screen and pop-up multitasking capabilities allow users to run two applications simultaneously—such as reviewing notes while attending a video call or referencing a spreadsheet while drafting an email. However, many popular applications (including certain banking utilities, social media platforms like Instagram, and video games) explicitly declare android:resizeableActivity="false" within their internal application manifests. When you attempt to open these applications in split-screen mode, Android blocks the action with a toast notification: “App doesn’t support split screen.”
To bypass this artificial developer restriction and force every installed application to participate in multi-window mode, Android includes an indispensable toggle in Developer Options: Force activities to be resizable.
What Does “Force Activities to Be Resizable” Do?
When you activate this setting, the Android WindowManager overrides the internal manifest declaration of every application installed on your device. Android treats every activity as if android:resizeableActivity="true" were specified, permitting the system to resize windows into split-screen mode, freeform floating pop-ups, and desktop workstation environments (such as Samsung DeX or Android 15 Desktop Mode).
Benefits and Potential Caveats
Overriding manifest restrictions provides immense productivity benefits, alongside minor interface quirks:
| Multitasking Aspect | Default Android Behavior | Force Resizable Enabled |
|---|---|---|
| Split-Screen Eligibility | Blocked if app manifest disables resizing. | Universally available across 100% of installed apps. |
| Pop-Up / Floating Windows | Restricted to approved applications. | Any app can be collapsed into a floating window. |
| Desktop Mode (DeX) | Unresizable apps open in fixed vertical phone boxes. | Apps can be freely maximized and snapped to desktop corners. |
| UI Scaling Edge Cases | None (apps run in fixed aspect ratios). | Minor layout stretching may occur in games designed strictly for fullscreen. |
Step-by-Step: Enabling Developer Options
If Developer Options is not already unlocked on your Android device:
- Open the Settings app.
- Scroll down and tap About phone (or About device).
- Locate the Build number entry.
- Tap Build number seven consecutive times until you see the confirmation prompt: “You are now a developer!”
- Confirm your lock screen PIN or biometrics when requested.
Activating Force Activities to Be Resizable
- Navigate back to the primary Settings menu.
- Tap System > Developer options (on Samsung Galaxy devices running One UI, select Developer options directly at the bottom of the Settings list).
- Scroll down to the Apps section near the bottom of the menu.
- Locate the Force activities to be resizable toggle.
- Switch the toggle to the ON position.
- Crucial Step: Restart your Android phone or tablet. A system reboot is required for Android’s package manager and activity manager services to re-evaluate installed application manifests with the override active.
Testing Split-Screen on Previously Blocked Apps
Once your device reboots:
- Open an application that previously refused split-screen (such as Instagram or a locked banking app).
- Open your Recents (App Switcher) screen by swiping up and holding, or tapping the square navigation button.
- Tap the application icon located at the top of the preview card.
- Notice that Split top (or Open in split screen view / Open in pop-up view) is now fully selectable.
- Select your secondary application to enjoy unrestricted side-by-side multitasking.
Frequently Asked Questions
Will enabling this setting cause unresizable apps to crash?
Modern Android frameworks handle multi-window configuration changes reliably. While a handful of heavy 3D games may display letterboxing or restart their activity when dragged across split-screen boundaries, standard productivity and social media applications function smoothly.
Does this setting stay enabled after Android OS updates?
Yes. Developer Options toggles generally persist across standard monthly security patches and minor OS updates unless Developer Options is explicitly turned off.