Apple is looking for a way to let websites use the full width of the iPhone Duo’s outer display. Today, Safari on the outer screen reserves a column on the right edge for controls, and web content stops at that column.
Jen Simmons from the WebKit team said so in the Safari 27.1 post on the WebKit blog, published the day the iPhone Duo arrived. Apple has not promised a fix or given a timeline. It only says it is investigating options.
Safari keeps web content out of the controls column on the outer display
The outer display is wider and shorter than the screen on other iPhones. To give pages more vertical room, iOS moves the controls for Safari and the phone itself to the side instead of the bottom. Safari fills that column with the page’s background color, but the content does not extend behind it.
Simmons wrote that Apple wants designers and developers to use that area in more creative ways. Her example is a header background that runs across the full width of the display.
The outer display is also tight for a webpage. Safari 27.1 gives websites a viewport 382 CSS pixels wide in portrait and 594 in landscape, with heights ranging from 368 to 618 pixels. Putting two windows side by side on the inner display in landscape lands at nearly the same width as the outer display in portrait, at 385 pixels per window.
Apple does not want to rely on viewport-fit cover
The obvious route is the HTML viewport meta tag with viewport-fit="cover", which pushes a page behind the system controls. Developers then use environment variables to keep important content clear of those controls.
Apple looked at how current sites are built and found many projects that fail to inset all four edges correctly. On those sites, text and buttons would end up hidden under the controls. Apple is investigating something more foolproof and easier to use, and Simmons asked developers to send in ideas and stay tuned.
Safari 27.1 adds side-by-side PDF pages and fold-aware web APIs
When the iPhone Duo is partially folded like a book, Safari 27.1 shows a PDF as two pages side by side. It switches back to a single page when the screen is flat or fully closed.
Developers get a preview of the Device Posture API and the Viewport Segments API, both behind feature flags. They can be switched on under Settings > Apps > Safari > Advanced > Feature Flags. The Device Posture API reports whether the screen is folded or continuous, while the Viewport Segments API describes the portions of the display on either side of the fold.
Developers who do not have the hardware can test with a simulator. Xcode 27.1 or later includes Device Hub, where an iPhone Duo simulator can be created.
