If you spend your day in one app at a time and judge a phone by its camera, buy the iPhone 18 Pro Max and save $700. If you regularly wish your phone were a small tablet, iPhone Duo is the only iPhone that answers that, and the $700 is the price of the answer.
Both phones run the same A20 Pro chip and the same iOS 27 features, so this is not a performance decision. It is a decision about shape, cameras and dates, and Apple has published enough to make it cleanly.
| Spec | iPhone Duo | iPhone 18 Pro Max |
|---|---|---|
| Starting price | $1,999 (256GB) | $1,299 (256GB) |
| Screen | 7.6-inch inner, 5.4-inch outer | 6.9-inch, 2868 by 1320 |
| Biometrics | Touch ID in the side button | Face ID |
| Rear cameras | 48MP Main and 48MP Ultra Wide | 48MP Main, Ultra Wide and 4x Telephoto |
| Zoom | 0.5x, 1x, 2x optical, 4x optical range | 0.5x to 8x, 16x optical-quality range |
| Battery (video) | 44 hours outer, 31 hours inner | 45 hours |
| Weight | 254 g | 249 g |
| On sale | October 23 | September 18 |
Buy iPhone Duo if the screen is the job
The reason to fold is the inner display, which Apple puts at 50 percent larger than the iPhone 18 Pro Max screen. That is a different working surface, not a bigger one, and iOS 27 treats it that way with Split View and layouts that adapt to how the phone is posed.
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It suits people who read long documents, keep a chat window beside a browser, watch on trains, or currently carry a tablet they use for an hour a day. Apple also says the 5.4-inch cover screen has more than 90 percent of the screen area of an iPhone 18 Pro, so shut, it still works as a normal phone.
One practical point that gets missed: the closed Duo is 11.3 mm thick against 8.75 mm for the Pro Max. It is barely heavier at 254 g against 249 g, but it is a thicker object in a pocket.
Buy iPhone 18 Pro Max if the camera decides it
The Pro Max keeps the 48MP Fusion Telephoto at 100 mm, the optical-quality 8x crop at 200 mm, and the variable aperture with stops at f/1.48, f/1.8, f/2.8 and f/4.0. The Duo has none of those, as our guide to the Duo camera system explains.
It also keeps Face ID, an 18MP front camera against the Duo 12MP outer camera, ProRes recording, and a slightly faster wired charge at 50 percent in about 15 minutes against about 20 minutes on the Duo. Battery is close to a draw on Apple published video playback ratings, at 45 hours against 44 hours on the Duo outer screen.
And it is available now. Pre-orders opened September 12 and the phone ships September 18, five weeks before the Duo.
Five questions that settle it
- How often do you want two apps on screen at once? Frequently favours the Duo, rarely favours the Pro Max.
- Do you shoot at 4x or 8x zoom? If yes, the Duo is the wrong phone at any price.
- Do you carry an iPad you do not really use? If yes, the Duo can replace it and the $700 stops looking like a premium.
- Do you need the phone this month? The Pro Max ships September 18, the Duo October 23.
- Do you rely on Face ID for banking apps and unlocking while wearing gloves? The Duo has Touch ID only.
What the two phones share
The overlap is larger than the price gap suggests, and it removes several arguments people are making about the Duo being a compromised device.
| Shared | Detail |
|---|---|
| Chip | A20 Pro, 2-nanometer, 6-core CPU, 7-core GPU, dual 16-core Neural Engine |
| Ultra Wide | 48MP, 13 mm, f/2.2, 120-degree field of view on both |
| Durability rating | IP68 to 6 meters for 30 minutes, Ceramic Shield 2 front |
| Wireless | Wi-Fi 7, Bluetooth 6, Thread, second-generation Ultra Wideband, C2 modem |
| Charging | MagSafe up to 25W, Qi2 up to 25W |
| Storage | 256GB to 2TB on both |
The one software difference worth knowing is that the Duo ships with iOS 27.1 rather than the iOS 27 release that lands September 14, because the folding layouts and Split View arrive with it.
Who we would actually send where
Photographers, travellers who live at long focal lengths, anyone upgrading for battery, and anyone who wants the phone before Halloween should take the Pro Max. That is most buyers, and it is not a consolation prize.
Readers, note-takers, people who run a second screen for work chat, and anyone who has wanted an iPhone that opens into something bigger should look at the full Duo and Pro Max comparison and then look at their own screen time. If the tablet-shaped hours are there, the Duo earns the money.
What Apple has not said
Apple has not published hinge longevity figures, repair costs for the folding display, memory, or battery capacity for either phone, and it has not published how the under-display inner camera performs against a conventional one.
iPhone 18 Pro Max is on sale now. iPhone Duo pre-orders open Friday, October 16 at 5 a.m. PT and it goes on sale Friday, October 23 in more than 70 countries, with 28 more following on October 30.
