iPhone Duo review: specs, price and release date

Design and displays: titanium, a hidden hinge and a nearly invisible crease

Apple's engineers focused on the two main complaints about foldables — fragility and a visible crease on the inner screen. The iPhone Duo's body is Grade 5 titanium with a mirror-polished finish, the front glass is Ceramic Shield 2 (three times more scratch-resistant than the previous generation, according to Apple) and the back is Ceramic Shield. The hinge has more than 100 components and its cover is 3D-printed from recycled titanium. Opened, it is the thinnest iPhone ever made — just 5.2 mm.

The crease. Apple does not promise it is gone, but uses two tricks: a custom nano-texture finish on the inner display (borrowed from the Studio Display) and optically clear adhesives that let the display layers glide as the screen folds. Early hands-on reviews agree: the crease is still visible in certain lighting, but it is hidden noticeably better than on Samsung's foldables, and the matte surface looks like a flat sheet of paper. The IP68 rating — up to 6 metres for 30 minutes — is rare among foldables.

Both displays share the same aspect ratio: an app open on the outer screen simply continues on the inner one when you unfold the phone, without re-layout. The outer display covers 90 % of the iPhone 18 Pro's screen area — closed, the Duo feels like a normal compact iPhone rather than the “narrow remote” early Galaxy Folds were criticised for.

A20 Pro, iOS 27 and Split View: two apps on one screen

At the heart of the iPhone Duo is the 2-nanometre Apple A20 Pro — the same chip as in the iPhone 18 Pro: a 6-core CPU (20 % faster than the A19 Pro), a 7-core GPU with Neural Accelerators (40 % faster) and a dual 16-core Neural Engine with twice the compute. For the first time an iPhone has a vapour chamber — Apple claims up to 35 % better sustained performance than the iPhone 17 Pro. As usual, Apple does not disclose RAM; supply-chain reports put it at 12 GB.

iOS 27 has been redesigned for the foldable form factor. The headline feature is Split View: two apps side by side with drag and drop between them (a photo from your library straight into Mail, for example). The Dynamic Island is now vertical, StandBy gets new Calendar and Weather faces, and a half-open Duo stands on its own — in the “Seated” position for video and workouts, in “Standing” for StandBy. Apple Pencil (USB-C) support is promised later this year.

Apple Intelligence on the Duo means the new Siri AI (in beta in iOS 27), which understands what is on screen and can act inside apps: create a calendar event from a chat, rewrite text, find a photo by description. Processing happens on device or in Private Cloud Compute, with no data shared with third parties.

Cameras: 48 MP Dual Fusion and tricks only a foldable can do

Don't confuse it with the iPhone 18 Pro: the Duo has two cameras, not three. The main one is a 48 MP Fusion Main (26 mm, ƒ/1.6, sensor-shift OIS) from which Apple derives an optical-quality 12 MP 2× telephoto (52 mm). The second is a 48 MP Fusion Ultra Wide (13 mm, ƒ/2.2, 120°) with macro. That gives a 4× optical-quality zoom range and digital zoom up to 10×. Video is 4K at 120 fps in Dolby Vision, and the cinematic effect can be applied after capture.

• Duo PreviewWhile you shoot, the outer display shows a live preview to the person being photographed, so they can fix their pose and framing themselves.
• Smart TakeThe camera detects the moment everyone in the frame is ready and takes the shot itself — no timer, no “one more”.
• Kid CuePlayful animations on the outer display draw a child's eyes to the lens — parents will appreciate it.
• Hidden FaceTime cameraOn the inner display the camera (ƒ/1.8) sits under the panel — no cutouts while you watch content.
• Center Stage outsideA 12 MP front camera on the outer display with automatic orientation detection and group selfies.

Battery, charging and connectivity: dual batteries and eSIM only

There are two batteries — one in each half. Apple does not quote mAh but gives runtime figures: up to 44 hours of video on the outer display, up to 31 hours on the inner display and up to 24 hours with equal use of both. Fast charging reaches 50 % in about 20 minutes with a 60 W adapter; MagSafe and Qi2 go up to 25 W (50 % in 30 minutes with a 35 W adapter). The USB-C port runs at USB 3 speed (10 Gb/s).

Connectivity: Wi-Fi 7, Bluetooth 6, Thread, NFC and 5G on Apple's own C2 modem. Important for Estonia: the iPhone Duo is eSIM-only — there is no physical SIM slot in any region. Telia, Elisa and Tele2 all support eSIM, but if you are moving from an older phone, check that your plan allows profile transfer. iPhone Handoff lets you switch between two iPhones on the same number.

iPhone Duo or iPhone 18 Pro Max: which to choose

The key question for anyone buying a flagship in 2026. The Duo costs roughly €700 more than a Pro Max in the same configuration, and trails it in three areas: no Face ID, no true telephoto lens and less battery headroom when the big screen is used heavily.

The Pro Max remains the pick for anyone who wants the best zoom camera, Face ID and a rugged slab. The Duo is for people who read, work with documents, watch video and want an iPad-mini-sized screen in their pocket. Weight is nearly identical and the chip is the same.

iPhone Duo vs Samsung Galaxy Z Fold8

Samsung has been making book-style foldables since 2019, and on pure engineering the Z Fold8 is thinner and lighter: 201 g versus 254 g, 4.5 mm versus 5.2 mm open. Apple answers with denser displays (430/460 ppi versus 404/428), an under-display inner camera instead of a cutout, stylus support, IP68 with 6-metre immersion and, above all, the ecosystem: iMessage, FaceTime, AirDrop, Apple Watch and Mac. European pricing: Z Fold8 from €1,929, Duo from €2,299.

iPhone Duo price in Estonia and release dates

In the US the iPhone Duo starts at $1,999. Apple's official European prices for the 256 GB model are €2,299 in Germany, €2,369 in Ireland and €2,419 in Finland — the difference is VAT only. For Estonia (24 % VAT) expect around €2,399 for 256 GB; official Estonian retail pricing will appear closer to launch, as there is no Apple Store in Estonia.

Pre-orders open on Friday 16 October 2026 (3 pm Tallinn time in Europe), sales start on 23 October in more than 70 countries, with 28 more countries following on 30 October. Apple has not published the full list of second-wave countries, so we will confirm Estonia's exact date as soon as it is announced. Official accessories: iPhone Duo Case at $79 and iPhone Duo Folio with Kickstand at $129.

Verdict

The iPhone Duo is not an attempt to catch up with Samsung but a rethink of the book-style form factor for Apple's ecosystem: matching display proportions, a hidden camera, a proper outer display and an iOS 27 that knows how to handle two windows. The price of that is weight, no Face ID and a bill of around €2,400.

Should you switch from a Pro Max? If you read a lot, work with documents, watch video or simply want to be the first in Estonia with a foldable iPhone in your pocket — yes. If a zoom camera and maximum battery life matter more, the iPhone 18 Pro Max at €1,650 remains the more rational buy.