An unfolded iPhone looks like a small book – and that's exactly how it will display PDFs in the future. A video shows the iPhone Duo's file preview with two pages side by side. For anyone who works with documents on the go, this is one of the most tangible reasons for the foldable format.
The video was published by the developer pdfu, who showcases it on X. It shows the overview, or file preview, of iOS, which is called Quick Look in English: When the iPhone Duo is opened like an open book, it displays a PDF with two pages side by side.
PDFu doesn't specify the source of the recording, and the post doesn't provide any reference to the code – it remains a video, not a document. The iPhone Duo will be released on October 23rd, shipping with iOS 27.1 – the view would therefore be part of that version.
Key Facts at a Glance
- A video shows the file preview of the iPhone Duo in its unfolded state with two PDF pages side by side.
- It was published by the developer pdfu, who does not disclose the source of the recording.
- The inner display of the iPhone Duo measures 7.6 inches.
- Apple plans to enable the Apple Pencil with USB-C for the iPhone Duo later this year.
Two pages on 7.6 inches
The inner display of the iPhone Duo measures 7.6 inches when unfolded, the outer one 5.4 inches. The dual-screen view utilizes the device's shape: to the left and right of the fold, a page is displayed, like an open magazine.
Quick Look on iPhone Duo has a new two-page layout in the open book position. https://t.co/gZtSH49rp1
— pdfu (@itspdfu) October 6, 2026
According to Apple, iOS 27.1 for the iPhone Duo brings dedicated layouts for the two displays and allows two apps to run side-by-side – the interface works seamlessly. File previews are another system feature that adopts the book format.
Later with the Apple Pencil
The view becomes even more interesting when used with the Apple Pencil. According to Apple's German press release, the iPhone Duo will later this year support the Apple Pencil via USB-C, on both the inner and outer displays. This support will not be activated at the launch date of October 23rd.
Only with the Pencil does reading documents become truly editable – annotations, signatures, and highlights. Apple doesn't mention the Apple Pencil Pro for the iPhone Duo.
A reading device that fits in your pocket
I consider the two-page view one of the details that justifies the folding format in everyday use. Contracts, scripts, invoices, or manuals are cumbersome to read on a regular iPhone; two pages side by side are closer to the experience of reading paper than any zoom.
For reading alone, the iPad mini remains superior to the iPhone Duo: its 8.3-inch display is larger and has no crease. The iPhone Duo's advantage is that when folded, it remains a regular iPhone and includes the e-reader.
Would you use the iPhone Duo as a document reader, or is that still a job for the iPad? Tell us in the comments how you feel.
