Apple just did something it hasn't done in nearly 20 years: completely change what the iPhone looks like. At the launch event on September 9, new CEO John Ternus (who took over from Tim Cook earlier this month) introduced the iPhone Duo, the company's first foldable iPhone, calling it "the biggest change to iPhone since the original."
I've read through Apple's official announcement and summarized what this phone has, what it costs, and who should — and shouldn't — buy it.
Two screens, one design
Think of it as two phones in one. Folded shut, it uses a 5.4-inch outer screen (5.36 inches measured as a standard rectangle, because of the rounded corners), which has 90% of the screen area of an iPhone 18 Pro. Unfold it and you get a 7.6-inch inner screen (7.58 inches measured as a standard rectangle), 50% larger than an iPhone 18 Pro Max, and the largest display Apple has ever put in an iPhone.
Both screens have the same aspect ratio (the shape of the display), so content fits properly when you switch from one to the other. Both also have ProMotion (a display that automatically ramps its refresh rate up for smoothness), an Always-On mode, and up to 3,000 nits of peak outdoor brightness.
The inner screen has a nano-texture finish that reduces glare and makes the crease less noticeable, and the FaceTime camera is hidden under the inner display, so there's no notch to distract the eye. There's no Apple Pencil support this year, but Apple says it'll come later this year via Apple Pencil (USB-C), for taking notes or drawing on either screen.
Pricing and release date (Thailand)
• 256GB — 79,900 THB
• 512GB — 87,900 THB
• 1TB — 103,900 THB
• 2TB — 127,900 THB
Compared with the regular iPhone 18 Pro starting at 48,900 baht and the iPhone 18 Pro Max starting at 52,900 baht, that means the Duo is roughly 27,000-31,000 baht more expensive than Apple's other flagships.
• Pre-orders open: October 16 at 7:00 PM
• On sale: October 23
• Colors: Star White and Night Sky (a deep blue)
• Installment option: 0% installments via credit card for up to 10 months, if you'd rather not pay the full amount at once
Design and durability: where Apple put in the most work
The Duo's body is made of grade 5 titanium (a metal that's strong but light) with a polished, glass-like surface, while the hinge cover is 3D-printed and made from 100% recycled titanium. The back glass uses Ceramic Shield, and the front display uses Ceramic Shield 2, which resists scratches 3 times better than the previous generation.
The phone is rated IP68, tested to the IEC 60529 standard, water-resistant to a maximum depth of 6 meters for up to 30 minutes (but Apple stresses that water resistance can degrade with use, and liquid damage is not covered by warranty).
The hinge (the part that lets the phone fold) is made of over 100 components that control opening and closing precisely and help keep the middle of the screen flat. Inside the body there are also support ribs and a split antenna design with a ceramic-fiber core reinforcing the frame's rigidity.
The inner display itself is designed to withstand daily use, with a scratch-resistant coating and a nano-texture surface layer made of a special polymer that's 40% harder than typical materials in the industry. The top and bottom of the foldable panel are backed by high-strength glass, and a special adhesive lets the material layers slide slightly against each other when folding (like pages in a book), reducing stress when the screen bends, with a titanium plate underneath for another layer of durability.
The trade-off: the Duo has no physical SIM card slot anywhere in the world — it's eSIM (a digital SIM embedded in the phone) only. Apple says removing the SIM tray freed up space for a larger battery.
Camera: a unique strength, but not Apple's best camera
The Duo has two rear cameras, not three like the iPhone 18 Pro:
• Fusion Main 48MP — captures sharp photos with zero shutter lag (no delay between pressing the shutter and the image actually being recorded), producing 24MP files by default for sharpness at an easily shareable size, and a built-in optical-quality 2x telephoto zoom (not a separate telephoto lens like the iPhone 18 Pro, but Apple calls it optical-quality). This camera also has a large sensor, a wide aperture, and sensor-shift OIS stabilization for better low-light shooting.
• Fusion Ultra Wide 48MP — the same one used in the iPhone 18 Pro, for wide-angle and macro shots.
What the Duo lacks compared with the 18 Pro: no separate telephoto lens (the 18 Pro has a 3-camera Pro system including a real telephoto), and no variable aperture (the feature that adjusts how much light enters the lens, exclusive to the 18 Pro).
The Center Stage front camera takes photos and video in any orientation automatically, so you don't have to rotate the phone for a landscape selfie. The FaceTime camera hidden under the inner screen lets you video call whether you're holding the phone unfolded or standing it up hands-free. FaceTime's Dual Capture feature can also send images from the front and rear cameras at the same time in a single call.
The foldable design also unlocks camera features exclusive to the Duo:
• Smart Take – on-chip AI analyzes the shot in real time and automatically presses the shutter when everyone's posed just right, so the photographer can get in the frame too.
• Duo Preview – shows a live preview on the outer screen, so the person in front of the camera can pose and check the composition themselves.
• Kid Cue – plays Peanuts cartoon animations on the outer screen to get a child's attention on the camera.
• Duo FaceTime – people sitting together can join a video call via the outer screen, without crowding around a single display.
For video, the Fusion Main camera shoots 4K at 120 fps in Dolby Vision (with adjustable playback speed for slow motion afterward), adds Cinematic effects after shooting at 60 fps, and Audio Mix has a new algorithm that separates music from speech better. There's also Camera Control (a shortcut button to the camera) with a new Siri Camera mode where Siri sees the same thing the user sees, to answer questions or do certain tasks immediately.
Chip and cooling system
The Duo uses the A20 Pro chip, the same as the iPhone 18 Pro, built on 2-nanometer technology. Apple says it delivers 35% better sustained performance (performance under continuous heavy load without throttling from heat) than the iPhone 17 Pro. The 6-core CPU is 20% faster than the A19 Pro, the 7-core GPU is faster and up to 40% more power-efficient, and the dual 16-core Neural Engine (the AI processing chip) delivers 2x the processing power, with 50% more memory bandwidth.
What helps the Duo dissipate heat well is a custom-designed vapor chamber (a chamber of vapor that absorbs heat from the chip and spreads it out quickly) connected directly to the chip, letting it handle heavy multitasking, gaming, or AI processing without throttling from heat.
Battery and charging
The Duo has two batteries, one on each side, working together as a single unit through Apple's power-allocation algorithm. Apple rates it for:
• up to 31 hours of video playback on the inner screen
• up to 44 hours of video playback on the outer screen
• up to 24 hours of mixed use, using both screens roughly equally
These numbers still trail the iPhone 18 Pro's 36 hours, because the 7.6-inch screen draws more power.
Charging: wired charging reaches 50% in about 20 minutes; wireless charging via MagSafe or Qi2 reaches 50% in about 30 minutes.
Unlocking: no Face ID
The Duo uses Touch ID (fingerprint scanning) built into the side button, usable whether the phone is on or off, and it can also be unlocked with an Apple Watch. Apple didn't mention Face ID at all in this launch, because fitting a face-scanning sensor into a foldable body is a much harder engineering problem.
iOS 27, redesigned specifically for foldables
The lock screen, the Dock on the home screen, and the various controls have been moved to the side of the screen to open up more vertical space for content. When unfolded, the screen shows 2 home screen pages with Today View (a scrollable list of widgets) on the left. The status bar is a shape-shifting circle that tucks into the corner of the screen, and the Dynamic Island has been redesigned to sit vertically along the side of both the inner and outer screens.
Apple's own apps include a new one called Detail, which uses the Core AI framework to do AI processing directly on the device (no cloud round-trip) to help create content more easily on the large inner screen. Third-party apps like Netflix, Zoom, and Slack have also updated their layouts to take advantage of this foldable.
New multitasking features that come with the Duo:
• Split View – open 2 apps side by side at once, a first on iPhone
• open 2 windows of the same app (such as Safari)
• talk to Siri AI while viewing content on the other side of the screen
• save frequently used app pairs to open together later
StandBy (the mode that displays information when the phone is set down at rest) also gets a big upgrade, working on both the inner and outer screens even when not plugged in, turning into a photo frame, a widget hub, or a clock, with new faces like calendar and weather.
A new version of Apple Intelligence and Siri
The Duo comes with an all-new beta version of Siri AI powered by Apple Intelligence, which understands the user's personal context better, can search across Messages, Mail, and Photos, and can answer questions and do certain tasks based on what's on the screen (onscreen awareness). It supports English only at first, with French, Japanese, Korean, Portuguese, and Spanish to follow in October (Thai is not yet on the supported list).
In the Phone app, the Call Context feature automatically pulls up relevant information when you call a shop or business, such as a confirmation code or booking number.
Other Apple Intelligence features that come with iOS 27 include reframing a photo's composition after the fact (Spatial Reframing, Extend), more accurate removal of distractions from a photo (Clean Up), and Notify Me in Safari, which alerts you when a website changes — for example when an item is back in stock or the price drops.
Wireless connectivity
The Duo uses 2 Apple-designed wireless chips: N1 (supporting Wi-Fi 7, Bluetooth 6, and Thread) and C2, a new cellular modem that uses AI to improve signal quality and stability, with support for mmWave frequencies in the US.
A new feature, iPhone Handoff, lets users switch the same phone number between 2 iPhones (at launch it only supports T-Mobile in the US and Telekom in Germany; it's unclear when it'll come to Thailand).
New accessories
Apple introduced 2 new cases alongside the Duo (the prices listed are US prices; there's no official Thai pricing in the information I have):
• iPhone Duo Folio ($129) – in navy and taupe, with a built-in stand that adjusts to various angles
• iPhone Duo Case ($79) – in sand and navy, a 2-piece design wrapping around both sides of the phone
Both work with MagSafe and the Qi2 wireless charging standard.
Environment
Apple says the Duo uses 35% recycled material by weight, with 100% recycled cobalt in the battery and 100% recycled titanium in the hinge cover. The manufacturing process uses 60% renewable energy (such as wind and solar), and the paper packaging is made from 100% paper pulp.
Who should buy the iPhone Duo
• People who want the biggest possible screen without carrying a separate tablet. The 7.6-inch screen is a clear upgrade for reading, watching video, or doing several things at once with Split View.
• Tech enthusiasts who want the newest thing first. If you like having the latest technology that's different from everyone else's and aren't too concerned about price, this is the most changed iPhone in years.
• People who travel abroad often. No physical SIM tray means eSIM only, which — if your carrier supports it well — is actually more convenient than a physical SIM.
Who should skip it for now
• People who prioritize camera quality. The iPhone 18 Pro has a real telephoto lens and a variable aperture that the Duo doesn't.
• People who need Face ID. If unlocking without touching the phone matters to you, this model doesn't offer it.
• People on a budget. At roughly 27,000-31,000 baht more than Apple's other flagships, this is a premium purchase, not an upgrade that suits everyone.
• People wary of first-generation hardware. Even though Apple explained a lot of the engineering detail of the hinge and screen, there's no disclosed hinge cycle rating or long-term crease-development figure yet. Waiting for real-world reviews before deciding to spend nearly 100,000 baht is a reasonable idea.
Verdict
The iPhone Duo is a genuinely ambitious phone. Apple poured engineering into the hinge, screen durability, cooling, and water resistance — the areas that most often go wrong in a first-generation foldable. But it's not a camera flagship (no real telephoto or variable aperture), it drops Face ID, and the price is considerably higher than Apple's already-expensive Pro series.
If you want the best iPhone camera or the best value, look at the iPhone 18 Pro starting at 48,900 baht. But if you want the most exciting iPhone in years and can accept the roughly 79,900-baht price, the Duo does deliver on what it promises.
