Hidden or inactive content that is, for example, behind another window. should not be visible to users of assistive technology as users may think they can interact with this content.

For non-images this can be done by setting the appropriate properties or states on an object or element so it is properly indicated to assistive technology as off-screen, obscured, or hidden.

iOS

UIView, UIControl, and UIImageView objects along with any custom objects descended from these are not accessibility enabled by default. Other UI elements such as UIButton and UILabel are accessibility enabled and must be accessibility disabled if they are not meant to be accessible.

iOS Example

[somethingDecorative setIsAccessibilityElement:NO];

iOS Failure

[somethingDecorative setIsAccessibilityElement:YES];  

Android

Developers should ensure that elements that do not convey meaning or information to a user are not focusable via theandroid:focusable property.

Android Example

//blue rectangle used for decoration that does not receive focus - in this case android:focusable is false by default
<ImageView android:layout_height="wrap_content" android:id="@+id/image_1" android:src="@drawable/blue"></ImageView>

Android Failure

//blue rectangle used for decoration that can receive focus
<ImageView android:layout_height="wrap_content" android:id="@+id/image_1" android:src="@drawable/blue" android:focusable="true"></ImageView> 

HTML

For images, provide alt text that is null ({code)alt="") or use CSS background images. For input fields not meant for the user, use the attribute type="hidden". For other inactive buttons and elements set the disabled attribute.

HTML Example

Button that is not currently used:

<button type="button" disabled="disabled"></button>   

HTML Failure

Button that is not currently used:

<button type="button"></button>  

Testing