From the 15 to the 18 Pro Max: more memory, longer battery life, and a shorter telephoto lens.

Every new iPhone Pro Max is sold as a step up. This report checks what actually changed across four generations, iPhone 15 Pro Max, iPhone 16 Pro Max, iPhone 17 Pro Max and iPhone 18 Pro Max, using Apple's own spec pages. It is for anyone deciding whether to replace an older iPhone Pro Max, or choosing between an older model and the newest.

The report compares the chip, memory, battery life and cameras. Design, display, materials and connectivity are not compared here. Within what it covers, it sets aside what is the same on all four and shows what differs: what you would notice after upgrading.

Why these four? They are the four most recent generations of Apple's larger Pro model. The smaller iPhone Pro has its own report, because its telephoto changed differently.

What the iPhone 18 Pro Max adds depends on the phone you have now.

The chip changed in every generation, from the A17 Pro to the A20 Pro, and so did battery life: Apple's video-playback figure rose each time, from 29 hours on the iPhone 15 Pro Max to as many as 45 on the iPhone 18 Pro Max. From the iPhone 17 Pro Max on, that figure depends on the market: models sold in the United States and Japan list 2 hours more than those in the other 6 markets. Memory changed once, from 8 GB to 12 GB at the iPhone 17 Pro Max. Apple does not publish memory, so that row comes from third parties.

On the 17 and 18, the telephoto lens itself is 4x, less than the 5x lens on the 15 and 16. The 8x Apple advertises uses part of that telephoto’s 48MP sensor to take a 12MP photo. So the newer phones do reach closer, but the 8x comes from cropping, not from the lens. The main camera is 48MP on all four.

Apple does not say whose camera sensors it uses, and it publishes no lab scores. Two kinds of outside source fill part of that gap: teardown firms, which take a phone apart and identify its parts, and camera labs, which score a camera under set test conditions. Neither is Apple, so their figures sit in a table of their own, and the notes under it say which scores can be compared with which.

If you have an iPhone 17 Pro Max, the iPhone 18 Pro Max changes the least of the areas this report covers: a newer chip, a variable aperture on the main camera and more battery life. Memory and the camera resolutions stay the same.

If you zoom in often, look closely before upgrading from a 15 or 16 Pro Max. From the 17 on, the telephoto lens itself is shorter, 4x instead of 5x, though it has four times the pixels, and the 8x Apple advertises is a crop from it.

If battery life is your reason to upgrade, every generation added some, and the iPhone 18 Pro Max lists the most: up to 45 hours of video playback in the United States and Japan.

Sensor details and lab scores come from third parties and do not yet cover every generation. As of 14 September 2026 we had found none for the iPhone 18 Pro Max.