Thinner phones are worse phones as iPhone 17 Slim and Z Fold 6 Ultra may prove

Typically, where those two go, others soon follow, so next year we might see a repeat of the Great Phone Thinning war of 2015 when many sub-8mm and even sub-7mm handsets battled for the thinnest phone title. 

Ever since those thin metal casts, though, phone makers moved to glass backs, huge batteries, and giant camera sensors, so thin was out. Now thin seems to be back in, but for what?

Are thin phones design marvels or specs laggards?

There simply isn’t enough space in a thin phone to cram all the top-shelf components that can go into a reasonably thick one. Granted, slimmer handsets are a thing of beauty, but mainly for the beholder, as those who own them will have to make do with weaker specs, questionable durability, and harder to cool processing power.

iPhone 17 Slim as iPhone Plus savior

The iPhone 17 Slim will undoubtedly be a looker, but it would come with non-Pro Apple A-series processor, the minimum amount of RAM needed to run Apple Intelligence, and a single camera on the back, albeit with variable aperture. We wouldn’t hold our breath for a big battery, either, as the pack would have to fit in a thinner body.

Granted, an iPhone 17 Slim is a good tactical move for Apple if it replaces the Plus line of iPhones that nobody seems to care about. It will then have a standout feature that can be pushed more in marketing materials, and could reinvigorate the lagging Plus sales. 

The iPhone 17 Slim may also be priced higher than the iPhone 17 Pro Max, though, at a rumored $1299 starting price, so it remains to be seen what the eventual uptake will be.

Samsung Z Fold 6 Slim as a forced release

Moving on to the Galaxy Z Fold 6 Ultra that may eventually also get the Slim moniker, we find more compromises that Samsung has reportedly had to make in the quest for elegance. Most focus groups on foldable phones point out that size, weight, and price are some of the main factors working against their mass adoption.

Armed with this knowledge, foldable phone makers created thin and light engineering marvels like the Honor Magic V3 that is only 9.2mm thick when closed and weighs 226 grams. For comparison, the iPhone 15 Pro Max is 8.25 mm without the camera bump, and weighs about the same. The Vivo X Fold 3 weighs less than the iPhone, and measures 10.2mm when closed, while the new Xiaomi Mix Fold 4 is 9.5 mm and weighs 226 grams, and so on. 

Of notable absence among these engineering marvels is Samsung’s Galaxy Fold line. The newest Z Fold 6, for instance, is 12.1 mm thick, and weighs 8.43 oz (239 g), an improvement from its predecessor, but still a far cry from what the Chinese phone makers are now able to craft.

Z Fold 6 is still thicker than the OnePlus Open | Image credit – PhoneArena

This reportedly made Samsung’s head honchos furious, and they asked the engineering team to address all complaints about foldable phones in one fell swoop. It had to be thinner than the others, lighter, and cheaper, too. This explains why we have intermittently been hearing rumors about a Galaxy Z Fold FE, Z Fold Ultra, and even Z Fold Slim line that was supposed to appear together with the Z Fold 6 and Z Flip 6 this summer.

When Samsung decided to set the Z Fold 6 FE apart, however, by making it at the same time thinner and cheaper, but still tough and more durable than thin Chinese foldables like the Magic V3, it hit a brick wall. Upon adding the needed water-resistance and ingress protection designs, the phone became thicker and actually only matching what Chinese phones already offer, tips The Elec in an interview with a local analyst. 

The Z Fold 6 slim model was planned with the goal of making it thinner than the regular model, but after applying the 200,000-fold folding test and water and dust resistance functions, it was found to be not thinner than the Chinese foldable phones, so a comprehensive review was conducted… [Samsung] ultimately decided to launch the product and see how the market reacts.

Analyst Jong Lee for The Elec, July ’24

At the same time, Samsung had to eschew many of the Z Fold 6 features to make the phone thinner and with lower production costs. The removal of the screen digitizer to make the phone slimmer means no S Pen support, while using a weaker processor to keep things on the cheap would make it slower. Samsung is apparently slimming down the Galaxy S25 Ultra as well, and as a result will ship it with the same battery capacity it’s been using since the S20 times.

It remains to be seen what the ultimate specs and price of Samsung’s Z Fold 6 Ultra or iPhone 17 Slim will be, but for now they seem to confirm the notion that thinner phones are worse phones when it comes to hardware, ergonomics, or durability. They do have those mighty good looks going for them, though.