Screenshot protection

// When the sensitive screen opens:
final result = await DeviceShield.setScreenshotProtection(true);

// When it closes:
await DeviceShield.setScreenshotProtection(false);

result is ProtectionResult.applied once the protection is in effect, failed if there’s no window yet (call it again once your UI is showing), and unsupported where the platform has none.

Android

The SDK sets FLAG_SECURE on your activity’s window. The operating system then:

• saves screenshots as a black image,
• shows black in screen recordings and casts, and
• hides the app’s thumbnail in Recents.

Verified on an Android 17 emulator (API 37): with protection on, both a system screenshot and adb screencap come out black, including after rotating the device.

App-switcher protection uses the same flag. The two are tracked separately: the flag stays set while either one is on.

iOS

Experimental: not yet verified on a device

iOS has no supported API for blocking screenshots. The SDK uses a widely used technique that relies on undocumented UIKit behaviour: content inside a secure text field’s internal layer is left out of captures. Any iOS update could change that.

On the iOS Simulator the protection installs and removes cleanly without affecting layout or touch. The Simulator can’t show whether captures are blocked, and this hasn’t been verified on a physical iPhone yet.

On iOS, pair it with screenshot detection and app-switcher protection rather than relying on it alone.