Introduction
Remember when phones were getting better every year? Now looks like they’re just getting thinner every year. The latest flagship ultra-thin smartphones — Samsung Galaxy S25 Edge (5.8 mm), Apple’s rumored iPhone 17 Air are chasing slimmer form factors to shave off every possible millimeter. But is this actually good for users, or just another marketing gimmick?
Let’s peel back the sleek exterior and examine the deeper concepts and rationale behind ultra-thin smartphones.
The original iPhone measured a now laughable 11.6mm thick. Fast forward to 2024, and we were seeing flagships routinely dipping below 7mm. When Samsung unveiled their Galaxy S24 Ultra at just 8.6mm thin while packing a 5,000mAh battery, competitors scrambled to respond. Not to be outdone, Xiaomi released their 13T Pro at a mere 8.49mm, while Motorola shocked everyone with the 5.9mm Razr 40 Ultra.
Why Are Brands Pushing Thinner Phones?
| Reason | Explanation |
| Aesthetic Appeal | Sleek designs look futuristic and minimalist — Easy to market and Instagram. |
| Differentiation | In a sea of similar specs, a thin profile stands out. |
| Weight Matters | Thin = light. Feels nicer in hand, especially for all-day use. |
| Pricing Psychology | A “slim tech marvel” sounds premium and justifies higher pricing. |
But this slimming trend raises an important question: are ultra-thin smartphones actually what consumers want, or what manufacturers think we want?
Also see The Upgrade Reality: Why You Don’t Always Need the Latest Tech
What’s the Real Cost of ultra-thin smartphones?
| Trade-Off | Impact |
| Battery Life | Less room = smaller batteries. Fast Charging helps, but physics limits capacity. |
| Camera Quality | Large sensors don’t fit well = bigger bumps or limited optics. |
| Thermal Management | Less space for heat dissipation = throttling under load. |
| Durability | Thinner frames are more prone to bending, cracking, and overheating. |
1. Battery Life Blues
Let’s talk physics: batteries take up space. According to research from Battery University, reducing a smartphone’s thickness by 1mm can decrease battery capacity by up to 15% [1]. That’s why many ultra-thin phones struggle to last a full day of moderate use.
“The obsession with ultra-thin smartphone has created a generation of phones that prioritize aesthetics over functionality,” says tech analyst Maria Chen in her TechCrunch analysis of modern smartphone design priorities [2]. “Consumers end up carrying power banks that make their overall setup bulkier than if they’d just had a slightly thicker phone with better battery life.”
2. Compromised Camera Systems
Camera bumps have become increasingly pronounced as phones get thinner. Manufacturers want to include powerful camera systems but don’t have enough internal depth to house them flush with the body.
“The physics of light capture means that camera sensors and lenses need a certain minimum depth to function optimally,” explains photography expert James Lin. “The thinner the phone body, the more the camera has to protrude, creating those unsightly bumps and making phones wobble on flat surfaces.”
3. Thermal Throttling: The Heat is On
Tests from AnandTech show that ultra-thin smartphone flagships can lose up to 30% of their processing power during sustained high-performance tasks compared to thicker phones with similar specs [4]. This means your thin gaming phone might actually perform worse than a thicker alternative.
4. Durability Dilemmas
The 2022 Allstate Protection Plans Breakability Score report found that phones under 7.5mm thick are significantly more likely to sustain damage from everyday drops compared to phones over 9mm thick [3]. That’s why an estimated 76% of slim phone owners use protective cases—ironically making their devices bulkier than if they’d started with a slightly thicker, more durable phone.
What We’re Trading Away for ultra-thin smartphones?
Headphone Jack: The First Casualty
Headphone jack was the first major feature sacrificed at the altar of thinness. When Apple removed it from the iPhone 7 in 2016, they cited “courage,” but the real reason was clear: making room in an increasingly cramped internal space.
Repairability Nightmare
iFixit’s repairability scores tell the story: ultra-thin smartphones consistently score lower than their sturdier counterparts [5]. The average repairability score for sub-7mm phones is significantly lower than for phones over 8mm thick, making repairs more difficult and expensive as phones get thinner.
Is This Actually Useful or Just a Gimmick?
Useful If You:
- Want a stylish, feather-light phone.
- Use your phone moderately (basic apps, browsing, calls).
- Prefer design over specs.
Gimmick If You:
- Need long battery life or high-end gaming.
- Value camera performance.
- Expect ruggedness or longevity.
A 2023 YouGov survey found that 83% of smartphone users would accept a phone 1-2mm thicker if it offered significantly better battery performance [6]. Meanwhile, only 12% considered “thinness” a top-five feature when choosing a new phone.
While the mass market often prioritizes battery life and comprehensive camera systems, some brands also seem to believe that there is enough demand for a premium, ultra-thin smartphone to justify the R&D and potential compromises.
The success of the models will ultimately depend on how well they balance the allure of a thin smartphone design with the practical expectations of battery life and camera capabilities at their premium price points.
The Sensible Middle Ground: Some Manufacturers Getting It Right
Not all manufacturers are caught in the thinness trap. Several brands have found success with a more balanced approach as well.
Phones like the ASUS ROG Phone 9 Pro don’t apologize for their 8.9mm thickness—instead, they celebrate what that extra space allows: a massive 5800mAh battery that can last two full days of heavy use.
Similarly, the Google Pixel 8 Pro maintains a reasonable 8.9mm profile while delivering excellent battery life and thermal performance. Their marketing focuses on real world benefits rather than dimensional bragging rights.
The Future Fix – Radical New Tech to the Rescue?
Here’s what could make ultra-thin but powerful smartphones a reality:
| Tech | What It Promises | Current Status |
| Silicon-Carbon Batteries | Higher energy density in smaller space than lithium-ion. | In R&D / early-stage deployment[7]. |
| Stacked Motherboards | 3D layering of internal components to save horizontal space. | Already in use (Apple, Xiaomi). |
| Graphene Cooling | Better heat dissipation with ultra-thin layers. | Experimental / niche flagships[8]. |
| Under-Display Everything | Hidden cameras, sensors, and even haptics to free up surface space. | Slowly rolling out [9]. |
| Foldable Hybrids | Bigger screen when needed, compact when not. | Maturing, but still bulky. |
Finding Your Balance: How to Choose Wisely
When buying your next phone, consider these factors beyond mere thinness:
- Battery capacity to thickness ratio: Look for phones that maximize battery size relative to their dimensions.
- Thermal performance reviews: Check how well the phone maintains performance during extended high-demand tasks.
- Phone Case necessity: If you’re definitely going to use a case (as most of us do), the phone’s original thickness becomes less relevant.
- Repairability scores: Sites like iFixit provide valuable information about how feasible repairs will be down the line.
- Your actual usage patterns: Heavy users should prioritize battery life and thermal performance over slimness.
What Should ‘You‘ Do as a User?
Don’t fall for the ultra-thin smartphone trap. Ask yourself:
- Will this phone last through your day?
- Is the design upgrade worth sacrificing camera or battery?
- Are you paying more just to get less?
If thinness doesn’t genuinely make your life easier, it’s not an upgrade — it’s a downgrade in disguise.
The good news? We may be approaching a thinness plateau. Technological limitations and consumer feedback are pushing some manufacturers to reconsider the value of shaving off those last few millimeters.
“We’re seeing a shift in design philosophy,” notes product designer Jeffrey Huang in his IEEE analysis of smartphone trends. “The future isn’t necessarily about making phones thinner, but about making them feel thinner through better ergonomics while maintaining the internal space needed for high-performance components.”
The next time you’re shopping for a smartphone, remember that thinness is just one dimension of design—and perhaps not the most important one.
What’s your take on ultra-thin smartphones? Are you willing to sacrifice functionality for fashion? Let us know in the comments!
References:
[1] Battery University. “BU-301: A Look at Old and New Battery Packaging.” 2023. https://batteryuniversity.com/article/bu-301-a-look-at-old-and-new-battery-packaging
[2] TechCrunch. “The Thin Phone Paradox: When Less Battery Means More Accessories.” https://techcrunch.com/2012/08/06/flexible-batteries-promise-thinner-and-lighter-foldable-electronics/
[3] Allstate Protection Plans. “Smartphone Breakability Risk Study.” https://www.squaretrade.com/press-release/allstate-protection-plans-finds-samsungs-smartest-smartphones-are-still-vulnerable/
[4] AnandTech. “The Apple A15 SoC Performance Review: Faster & More Efficient.” 2021. https://www.anandtech.com/show/16983/the-apple-a15-soc-performance-review-faster-more-efficient
[5] iFixit. “Smartphone Repairability Scores.” 2023. https://www.ifixit.com/smartphone-repairability
[6] FirstPost. “What Smartphone Features Do Indians Value Most?” what-do-indians-looks-for-in-a-smartphone-new-study-reveals-changing-priorities
[7] IEEE Spectrum. “Silicon Batteries Are Coming, and They Could Make Electric Cars Work.” 2022. https://spectrum.ieee.org/silicon-anode-battery
[8] Quora-Graphene can help cool cell phone chips. https://lipolytim.com/graphene-instead-vapor-chamber/#conclusion-why-apple-chose-graphene
[9] IEEE. “Research on Under-Display Camera Technology for Mobile Devices.” 2022. https://ieeexplore.ieee.org/document/9577345
