Apple is currently exploring methods to optimize the Safari browser interface for the outer screen of the iPhone Duo. The current design places navigation controls on the right side of the wide, short display, which restricts the horizontal space available for web content and leaves unused areas filled with background colors.
WebKit engineer Jen Simmons noted in the Safari 27.1 developer notes that while the viewport-fit=cover property allows content to extend beneath controls, it often results in UI elements overlapping with system controls. The team is investigating solutions such as extending the title bar background while keeping navigation buttons in accessible positions.
Safari 27.1 introduces specific features for foldable devices, including a dual-page view for PDFs when the iPhone Duo is partially folded. The browser automatically reverts to a single-page layout when the device is fully opened or closed. Developers can also use experimental features to detect folding states and manage content placement around the screen crease.
These new capabilities are currently available in developer preview mode and require manual activation via feature flags in the Safari advanced settings. Apple emphasizes that Safari 27.1 maintains compatibility with existing WebKit engines and encourages developers to continue prioritizing responsive design principles for all web content.
