For many months, tech blogs like ours used the name iPhone Ultra to refer to Apple's rumored foldable iPhone, but the device ended up being named iPhone Duo.

The name iPhone Duo was not a complete surprise. Daring Fireball's John Gruber accurately guessed that the device would be named iPhone Duo all the way back in April, and the name made the rounds again on social media last week.
iPhone Ultra became the more common name in rumor coverage after Bloomberg's Mark Gurman floated it as a potentially fitting name for the device back in March, and he later reported that many Apple employees referred to the device as the iPhone Ultra. Plus, former Macworld reporter Filipe Espósito cited a source familiar with Apple's plans who said the foldable iPhone would be named iPhone Ultra. Evidently, that source was wrong.
To his credit, Gurman ended up confirming the iPhone Duo name in a last-minute report published shortly before Apple announced the device.
Apple avoiding the name iPhone Ultra makes sense, as the device now known as the iPhone Duo is not the most "ultra" version of the iPhone available. Yes, the iPhone Duo has a large 7.6-inch inner display when opened, but on the other hand the device lacks features such as a dedicated Telephoto camera, Face ID, and an Action button.
Apple has used Duo branding in the past for its PowerBook Duo line of laptops in the 1990s and the MagSafe Duo Charger in the early 2020s. In the case of the iPhone Duo, the word Duo obviously refers to the device's dual screens.
Apple does have some products and services with Ultra branding, including the Apple Watch Ultra, CarPlay Ultra, and the M1 Ultra through M5 Ultra line of chips. And with Apple rumored to be a planning a special 20th-anniversary iPhone, perhaps there will still be an opportunity for the company to use the name iPhone Ultra in the future.
For now, though, the iPhone Ultra rumor is dead.



















