Cross-platform · Foldables

iPhone Duo vs Galaxy Z Fold 7 — a developer's comparison

Shipping a foldable-ready app on both platforms? The devices look similar, but the layout systems, aspect ratios, and testing tools differ. Here's what actually matters when you write the code.

Display comparison

	iPhone Duo	Galaxy Z Fold 7
Outer display	5.4″ · 466 × 678 pt (1398 × 2034 px @3x)	6.5″ · 2520 × 1080 px · 21:9
Inner display	7.6″ · 669 × 951 pt (2007 × 2853 px @3x)	8″ · 2184 × 1968 px · ~20.9:18
Outer aspect	Taller than 2:3 — phone-like	21:9 — very tall and narrow
Inner aspect	~7:10 — near-square, iPad-like	~20.9:18 — near-square, slightly wider
Refresh rate	ProMotion (adaptive)	1–120 Hz adaptive (both displays)

How each platform handles the fold

	iPhone Duo (iOS 27)	Galaxy Z Fold 7 (Android 16)
Layout system	SwiftUI size classes — outer is `compact × regular`, inner is `regular × regular`	Jetpack WindowManager — window size classes (compact / medium / expanded)
Fold event	Trait-collection / geometry change while running — re-render on size class flip	`FoldingFeature` — posture (flat / half-opened) and hinge bounds as data
Hinge handling	No hinge API — keep controls off the center strip by convention	Hinge position exposed via API — can lay out around it explicitly
Multi-window	Stage Manager / Split View idioms carry over from iPad	First-class multi-window + app pairs; users expect it
Simulator	Xcode 27.1 beta, poses as Device Hub buttons	Android Emulator with foldable hardware profile, hinge angle control

What this means in practice

One responsive layout can serve both inners. The Duo's inner display (regular × regular) and the Fold's expanded window class both want a two-column, tablet-like layout. Design to the window class, not the device.
The outers need separate attention. The Fold's 21:9 cover is dramatically narrower than the Duo's outer display — single-column layouts must survive both.
Test the transition, not just the states. Both platforms resize your app live during the fold. State loss mid-fold is the #1 foldable bug on either OS.
Android gives you hinge data; iOS doesn't. If your layout adapts to the exact hinge line on the Fold, keep a convention-based fallback (center-strip avoidance) for the Duo.

Duo-specific resources

Exact Duo geometry: device specs · Copy-paste layout code: SwiftUI snippets · Everything to verify: adaptation checklist.