Accessibility on iPhone Duo: VoiceOver, Dynamic Type, and every device pose

Why device poses complicate accessibility specifically

A sighted user visually confirms a layout looks correct on a given screen. A VoiceOver user experiences your interface through a reading order and a set of accessible actions, which are much easier to get subtly wrong when your layout logic reorganizes content between the outer display, the inner display, and Split View. A control that reads in a sensible order on the inner display can end up in a confusing order once the same content is compressed into the outer display's smaller frame, especially if your reading order is inferred from visual position rather than declared explicitly.

What to actually test

A few concrete checks worth running on every iPhone Duo-aware view:

• Turn on VoiceOver and navigate your interface fully folded, fully unfolded, and in Split View paired with another app, confirming the reading order stays logical in all three
• Test with the largest Dynamic Type sizes on the outer display specifically, since it has the least room to work with and is the pose most likely to truncate or overlap text
• Check contrast in both light and dark appearance across all three poses, since background material and system chrome can shift subtly between the outer and inner displays

Lean on system containers

Apple's guidance points toward standard system components like NavigationSplitView and UITabBarController specifically because they handle fold avoidance and vertical bar adaptation automatically — and, not coincidentally, they also tend to get accessibility behavior right by default in a way that fully custom layouts often do not. If your interface is currently built from custom containers rather than system-provided ones, that is worth revisiting for accessibility reasons as much as for the layout reasons covered in our adaptive layouts guide.

Protecting content near the fold

For custom UI that cannot be swapped for a system container, use Apple's reserved-region APIs to keep content clear of the fold and camera cutouts — a control that VoiceOver can technically reach but that is partially obscured by the hinge is a real, physical accessibility problem, not just a visual one.