Apple's first foldable has now been through a full review, and the verdict from heise online's Holger Zelder is a single word: it closes. "Klappt!" — it works, the hinge folds, the concept holds.
The design premise is the part worth understanding. Apple did not glue two large, thin displays together and load iPadOS, the way much of the category did. The Duo unfolds from an unusually small phone into a thin, almost-iPad with Pencil support. Closed, that means a compact outer screen; open, a substantially larger inner one, with the outer surface smooth and the inner matte.
The hinge is the engineering story. Apple says it consists of more than 100 components, and the test describes the mechanism as very solid: nothing rattles, the phone does not spring open on its own, and the hinge holds both halves in position even when partly open. Opening takes some force — possible with two fingers, awkward one-handed.
Around that core sit the details that decide whether a foldable is a phone or a gadget. There is Touch ID rather than Face ID, multitasking reworked for the two-screen arrangement, a battery split between the two halves, MagSafe accessories and Pencil support that the test finds works well but is more limited than on an iPad. The camera system was tested as part of the package rather than as a headline feature.
The bill is where the enthusiasm cools. heise describes the folding construction as elaborate and the repair costs as high, and frames the conclusion around the limits that the form factor and the price impose. That framing is consistent with the rest of the Duo's launch: a $1,999 device whose delivery dates have slipped into 2027, whose matte top layer Apple will replace for $19 only with AppleCare+, and whose inner displays have been reported cracking at the hinge — a problem Apple has acknowledged in a small number of units and is replacing, and which iFixit has traced to hinge components.
None of that makes the review a verdict on durability; it makes it a verdict on the idea. On the evidence heise published, Apple's bet — that a foldable should behave like a small phone that becomes a thin tablet, rather than two big panels pretending to be one — survives contact with daily use. Whether the hardware survives contact with a pocket for two years is a question no launch review can answer, and the first month of cracking reports suggests it is not a rhetorical one.
The full test, including display measurements, performance, camera results and battery runtime, is subscriber-only on heise+.
