Choose based on the shape of screen you need, not diagonal inches alone. Apple lists iPhone Duo at C$2,999 and iPhone 18 Pro Max at C$1,899 in Canada. Duo is a foldable with a 7.6-inch inner display and a 5.4-inch outer display; Pro Max has one 6.9-inch display. The listed starting-price difference is C$1,100 before tax.
This is a comparison of dated manufacturer specifications, checked 5 October 2026. We have not completed independent hands-on testing of Duo, so comfort, folding behavior, durability, and real-world battery performance are not scored here.
Published specifications
| iPhone Duo | iPhone 18 Pro Max | |
|---|---|---|
| Canada starting price | C$2,999 | C$1,899 |
| Displays | 7.6-inch inner folding OLED and 5.4-inch outer OLED | 6.9-inch OLED |
| Body dimensions (width × height × depth) | Open: 164.6 × 117.8 × 5.2 mm; folded: 84.1 × 117.8 × 11.3 mm | 78.0 × 163.4 × 8.75 mm (single body) |
| Weight | 254 g | 249 g |
| Storage options | 256GB, 512GB, 1TB, 2TB | 256GB, 512GB, 1TB, 2TB |
| Launch operating system | iOS 27.1 at Duo availability | iOS 27 |
Screen diagonals and dimensions describe different shapes and use states. Duo’s larger display number is its unfolded inner display; it is not directly comparable to Pro Max’s single slab display. Apple lists Duo’s dimensions in both open and folded states. The Pro Max dimensions describe its single body. Measurements do not establish pocket comfort or one-handed reach.
Which published design points toward your needs?
Duo is the foldable option. Its outer display is smaller than Pro Max’s screen, and its inner display opens to a larger workspace. That may suit someone who wants both a compact folded screen and a tablet-like surface in one device. We have not tested how well particular apps use that space.
Pro Max is the conventional single-screen option. Its 6.9-inch display is available without unfolding, and Apple’s Canadian starting price is lower. The specification table does not determine whether its camera, battery, or performance is better for your own use; those require evidence and a defined workload.
What this comparison cannot answer yet
- How Duo’s hinge feels over time, or how its inner screen handles everyday use.
- How quickly apps adapt when the device folds or unfolds.
- Whether either phone feels comfortable in a pocket or during one-handed use.
- Comparative battery life under the same reproducible workload.
- The best value for a particular storage, carrier, trade-in, or financing choice.
These are open test questions, not implied advantages. Recheck Apple’s current Duo specifications and Pro Max specifications before purchase.