One of them still takes a SIM card.

Apple's iPhone Duo and Samsung's Galaxy Z Fold8 are both phones that fold open to a 7.6-inch main screen. This report puts them side by side as sold in Hong Kong, using only what each maker states on its own Hong Kong spec page.

Comparing two makers is harder than comparing two iPhones. Apple and Samsung describe their phones in different terms and measure some things differently, so two numbers in one row can look comparable when they are not. Where that happens, the report says so rather than picking a winner.

Why these two, and why Hong Kong? Both open to a main screen of the same stated size, so a buyer looking at one is likely to weigh the other. Comparing within one market keeps every row about phones sold in the same place, and Hong Kong is a market where both makers publish a full spec page.

For many buyers one row decides it: in Hong Kong the Galaxy Z Fold8 takes a physical nano-SIM card, and the iPhone Duo takes none, in any of the 8 markets we read.

Two rows are the same: both makers state 2x optical-quality zoom and a 7.6-inch main screen, though each measures a folding screen its own way. Three rows differ. The Fold8 takes a nano-SIM and the Duo does not; the Duo weighs 254 g, 53 g more than the Fold8; and the rear cameras are 48MP + 48MP on the Duo against 50 MP + 50 MP on the Fold8. The remaining rows cannot be settled from the two spec pages, and each says why.

Two makers do not share a vocabulary or a measurement method, and each publishes the numbers on which it looks best. Where a pair of values are not two readings of the same quantity, this page shows both, says so, and declines to pick a winner. Refusing to answer is less satisfying than a verdict, and it is the only answer that will not mislead you.

If you need a physical SIM card, for a carrier without eSIM or for local SIM cards when you travel, the Galaxy Z Fold8 is the one of these two that takes one.

If weight matters most, the Fold8 is the lighter phone, by 53 g.

On battery life, speed and memory, the two spec pages cannot tell you which phone is better. Look for independent tests that measure both phones the same way.

If you choose the iPhone Duo, the version you get still depends on where you buy it; the iPhone Duo report under See also covers that.