The phone market has seen its fair share of ground-breaking and unconventional developments. While some inspired/forced the industry to embrace, others left a terrible taste in the mouths of users and manufacturers and will never be seen again. However, several concepts piqued our interest but failed to gain traction due to technological obstacles. One of them was skinny phones, a category that vanished like a passing fad. Fast forward a decade and tiny phones appear to be making a comeback. But, why now? Let us find out.
Why The Sudden Emergence of Slim Phones?
If you’ve been following the smartphone market, you may be aware of the impending Galaxy S25 Edge. For those unfamiliar, the S25 Edge (formerly reported to be the S25 Slim) signals Samsung’s return to the slim phone market. The change appears to be influenced by Apple’s anticipated iPhone 17 Air, which is also expected to arrive very soon.
The Korean powerhouse’s motivation is likely to keep ahead of the competition, which is understandable. Although Samsung appears to be going too fast in that pursuit, opting for a smaller 4,000 mAh battery. While it should survive reasonably long, it is far from the finest that Samsung could have provided. I’m talking to the probability that Samsung thoroughly tested the Silicon-Carbon batteries.
At MWC 2025, smartphone company Tecno unveiled the Spark Slim, which has a 5,200 mAh battery and measures only 5.75 mm. This is due to Silicon-Carbon battery technology, which has a denser Silicon-Carbon anode that can store more power than typical Lithium-ion’s graphite anode. What was the result? A 20-30% increase in overall capacity while maintaining the same or smaller dimensions as lithium-ion.
The forthcoming Slim phones, the Galaxy S25 Edge and the iPhone 17 Air, are expected to be 5.84 mm and 5.5 mm thin. Given Apple’s and Samsung’s tendency to be late adopters of new technology trends, we may infer that neither will use Silicon Carbon batteries. In 2025, we should expect more compact phones to appear as Android firms try to copy Apple.
A Look Back at Early Slim Phones
Those who have followed the smartphone space from the early 2010s may be aware that Samsung has a history of producing thin phones. The Galaxy A8, released in 2015, was the company’s thinnest modern smartphone, measuring only 5.9 mm. Other manufacturers quickly followed suit. For example, the Vivo X5 Max was the slimmest phone ever produced, measuring just 4.75 mm.
Likewise, the OPPO R5 measured 4.85 mm, while Motorola’s Moto Z measured 5.2 mm. My 14-year-old self remembers seeing X5 Max advertisements all over the streets. And my brain was left in wonderment, wondering just how small these phones could get.
Some of these phones included AMOLED panels, respectable mid-range processors, and, shockingly, headphone jacks despite their tiny design. Not only that, but Vivo managed to include a Yamaha DAC in the X5 Max. However, in these devices, battery capacity was treated as an afterthought. The phones barely lasted three hours on a full charge, thanks to their 2,000 mAh batteries, extremely power-hungry 1080p displays, and inefficient 28nm SoCs.
Moto had a remedy for the short battery life with the custom Mods on the original Z and Z2, but the Mods had a terrible reaction, and the Z series had its own challenges to contend with, namely software optimizations and quality control. Perhaps the Z series wouldn’t have ended so terribly if Moto had attempted to address these flaws. Firms quickly realized they lacked the necessary technology to make it work. Despite their best efforts, thin phones were quickly phased out of existence. But, after a decade of breakthroughs in optics and batteries, would thin phones finally be successful? To address that, we must draw comparisons with another form factor.
Are “Slim” Phones The New “Small” Phones?
It’s clear that manufacturers are returning to slim phone design in order to provide users with handsets that are easy to handle and carry. If that notion sounds familiar, it is precisely what propelled tiny phones forward. So, are skinny phones the new smaller phones? Although I would have rejoiced louder if Silicon-Carbon batteries were employed in small phones, slender phones could serve a few purposes. They should be comfortable to carry, portable, and visually appealing. All of these are true advantages, but they may still feel extremely narrow, especially when compared to small phones.
Small phones, on the other hand, satisfy a major consumer want/need, namely one-handed use, making them slightly more desirable and practical than slender phones. Furthermore, tiny phones, due to their form factor, naturally excel in giving a better in-hand feel and pocket-friendly design. Therefore, between the thinner form factor and larger screen, or enhanced pocketability and one-handed use, the majority would select the latter.
The final truth is that shaving a few millimeters off the thickness often results in a smaller battery (still), worse optics due to space constraints, impaired structural integrity, and performance throttling. These trade-offs may not be worthwhile for the majority of users. While the slim vs small phone debate is worth continuing, it’s vital to note that both form factors are extremely narrow. However, unlike compact phones, slim phones do not solve any important concerns other than looking beautiful.
While advancements in battery technology, efficient CPUs, displays, and other components may postpone their doom, it is a form factor that requires sacrifices and may not endure as a result. Slim phones are effectively challenging the small phone industry, but small phones are simply more convenient.
Who Are Slim Phones For? Will They Survive the Next Wave?
Slim phones are clearly aimed at business professionals, executives, influencers, trendsetters, and aesthetic-focused users who value minimalism. Slim phones, while improved over the course of a decade, are still primarily for aesthetic reasons. And I believe that’s where marketers need to reimagine this sector to appeal to both slim and small phone enthusiasts. That’s something OnePlus hopes to accomplish with its upcoming compact phone, the OnePlus 13T. While the exact specifications are unknown, the phone’s purported 6.32-inch screen, 7.8 mm thickness, and 5,800 mAh battery suggest it could be the ideal middle ground. Furthermore, the Xiaomi 15 is another “small” but relatively slim device that you can buy, measuring 6.3 inches and 8.1 mm.
The truly small phone category disappeared with the iPhone SE 3, although phones like the Galaxy S25 (review), Pixel 9 (review), and Xiaomi 15 (impressions) continue the legacy. They have smaller displays with thinner bezels, resulting in enhanced reachability and pocketability. A couple of them have a Silicon-Carbon battery, which, paired with their already “slim” form-factor, makes slim phones appear obsolete. While the Galaxy S25 Edge may still outperform them in terms of slimness, the gap will narrow even further (pun intended) when more manufacturers adopt the new battery technology. This could eventually make the trade-offs appear less significant, resulting in the second demise of thin phones.
What are your thoughts about slim phones? Do you believe these are better than little phones? Please let us know in the comments below.