Is the screen of a foldable smartphone easily breakable?

The inner display is a laminate of plastic and ultra-thin glass, and is more vulnerable to scratches than the strengthened glass of slab-type devices. It is easily damaged by drops or pressure, so use with a protective case is assumed. Repair costs are also high, so warranty coverage must be checked.

Is the step at the crease noticeable?

A shallow dent remains in the center and can be seen in angled light. It is less noticeable when watching videos, but may be noticed on documents with white backgrounds. It is important to check reflections on an actual unit in store and determine an acceptable range.

Do they support waterproofing and Osaifu-Keitai mobile wallet?

Support varies by product. The Galaxy Z Fold6 and Pixel 9 Pro Fold support IPX8 waterproofing and Osaifu-Keitai. Dust resistance is weaker than slab-type devices, so care is needed when using them in dusty environments.

Which should I choose, flip-style or book-style?

Flip-style is suitable for portability priority, and book-style is suitable for working-area priority. Flip models are lightweight and less expensive, while book-style models are strong in split-screen display. It is advisable to compare weight and usability of the outer display and decide based on primary use.

Gadgets

What Is a Foldable Smartphone? How It Works and How to Choose [2026 Edition]

How foldable phones work, flip vs. fold differences, pros and cons, and buying tips, plus weight and price comparisons.

September 12, 2026 6 min read Reviewed & edited by the SINGULISM Editorial Team

foldable smartphonesGalaxy ZPixelOLEDmobile devices

What Is a Foldable Smartphone

A foldable smartphone is a mobile phone device with a structure that allows the display itself to fold. It combines a flexible OLED display with a multi-axis hinge, allowing the screen area to be changed by opening and closing. The market took shape starting with the launch of the Galaxy Fold in 2019. As of January 2026, Samsung, Google, Motorola, and others offer products in Japan. The operating system is shared with slab-type devices, and most products run Android.

How It Folds

There are three core elements: flexible OLED, ultra-thin glass, and the hinge mechanism. Flexible OLED uses a thin plastic substrate instead of a glass substrate. It distributes the stress caused by bending and is designed to withstand hundreds of thousands of open-close cycles. The surface uses ultra-thin glass called UTG. It is about 30 micrometers thick and is layered with resin to prevent cracking. The hinge holds angles in place with multiple gears and leaf springs. The official Samsung Japan specifications (https://www.samsung.com/jp/smartphones/galaxy-z-fold6/) state durability for opening and closing and support for IPX8 water resistance. Many products use a waterdrop-style hinge to reduce the gap when closed. The protective film over the crease is a structural component and is not intended to be peeled off.

Two Main Types

They are broadly divided into book-style and flip-style models. Their uses are clearly different.

Horizontal Fold Type

When opened, it becomes a nearly square display in the 7- to 8-inch class. Representative examples are the Galaxy Z Fold6 and Pixel 9 Pro Fold. It is suited to parallel work such as viewing documents and spreadsheets or comparing maps. When closed, calls and notification checks are handled on the slim outer display.

Vertical Fold Type

When opened, it becomes a tall display of 6.7 to 6.9 inches. Representative examples are the Galaxy Z Flip6 and motorola razr 50. When closed, it is half the size and highly portable. The small outer display can be used for camera previews and payment confirmation.

Variants

Products with a tri-fold structure have also appeared. The Huawei Mate XT achieves an expansion to the 10-inch class. It is not sold in Japan, and issues remain with pricing and repair support.

Advantages

It combines portability with screen area. It fits in bags or clothing pockets.
Split-screen multitasking is easy. Reference materials can be viewed while writing documents at the same time.
Hands-free shooting is possible by fixing the angle. Still photography can be done without a tripod.
Only the outer display can be used when closed. Power consumption for checking notifications can be reduced.
Visibility for e-books and drawings is high. A single page can be displayed large. In practice, they are used for checking drawings on the move and comparing products in stores. They are highly rated in jobs that combine fieldwork and desk work.

Disadvantages

Thickness and weight increase. Book-style models reach 240-260g.
A crease remains in the center of the display. It may be visible in reflected light.
Prices are high. Book-style models cost around 250,000 yen as a guide.
Dust resistance is weaker than slab-type devices. Even with IPX8 support, care is needed against dust ingress.
Battery life is limited. Power consumption is fast when using the large screen.
Some apps are incompatible. Black bars may appear when the aspect ratio is unexpected. Repair costs are also high. Inner display replacement can exceed 70,000 yen in some cases.

How to Choose: Six Key Points

1. Form Factor

If multitasking is the main purpose, choose a book-style model. If portability is the priority, a flip-style model is suitable.

2. Weight and Thickness

Over 200g places a heavy burden on one-handed operation. Check the feel in hand when opened and closed at a store.

3. Usability of the Outer Display

For flip-style models, usability changes with the size of the outer display. 3.4 inches or larger is a good guide.

4. Water and Dust Resistance and Durability

IPX8 means resistance to submersion and does not guarantee dust resistance. A protective case is essential in dusty environments.

5. Processing Performance and Update Support

SoCs are mainly Snapdragon 8 Gen 3, Tensor G4, and others. Some products offer 7 years of OS updates, which affects maintenance costs for long-term use. The Google Store specifications (https://store.google.com/jp/product/pixel_9_pro_fold) state 7 years of update support.

6. Price and Connectivity

Book-style models are expensive and typically require installment payments or trade-ins. Flip-style models include products around 100,000 yen and are easier to adopt. Check the combination of eSIM and nanoSIM and supported frequency bands.

Comparison of Major Products [2026 Edition]

Figures are based on announced values for Japan and direct sales prices. Prices are subject to change.

Galaxy Z Fold6: 7.6-inch inner, 6.3-inch outer. Weight 239g. Snapdragon 8 Gen 3. IPX8. Street price around 250,000 yen.
Pixel 9 Pro Fold: 8.0-inch inner, 6.3-inch outer. Weight 257g. Tensor G4. IPX8. Supports 7 years of updates.
Galaxy Z Flip6: 6.7-inch inner, 3.4-inch outer. Weight 187g. Strong in portability and hands-free shooting.
motorola razr 50: 6.9-inch inner, 3.6-inch outer. Weight 188g. Easy to adopt with a street price around 100,000 yen. For camera priority, the Fold6 and Pixel are advantageous. Their telephoto and night-scene processing are highly polished. For lightness and price, the razr 50 is highly rated. It is suitable as a first foldable.

Suitable and Unsuitable Uses

Suitable uses are proofreading documents, referencing drawings, watching video while traveling, and displaying recipes while cooking. Fixed-angle positioning and the large screen improve work efficiency. Unsuitable uses are prolonged one-handed operation, continuous use in dusty environments, and strict color management. Crease reflections and color shifts are limiting factors. For mobile gaming, pay attention to unsupported screen ratios.

Editorial Opinion

In terms of evaluation criteria for comparison, we believe operational load when opening and closing should be prioritized over screen dimensions. Weight and thickness, and whether one-handed operation is possible, determine continued use. Since processing performance and cameras are on par, it seems reasonable to treat them as differentiating factors.

We see the pitfall in the field as a lack of understanding of waterproof specifications and the protective film. IPX8 in catalogs does not mean complete dust protection. Use in dusty environments and peeling of the protective film can cause failures.

Regarding future direction, we expect thinner designs and lower prices to proceed in parallel. Tri-fold devices and affordably priced flip models will broaden the options. Narrowing the price gap with slab-type devices is likely to be the condition for wider adoption.

References

Frequently Asked Questions

Is the screen of a foldable smartphone easily breakable?: The inner display is a laminate of plastic and ultra-thin glass, and is more vulnerable to scratches than the strengthened glass of slab-type devices. It is easily damaged by drops or pressure, so use with a protective case is assumed. Repair costs are also high, so warranty coverage must be checked.
Is the step at the crease noticeable?: A shallow dent remains in the center and can be seen in angled light. It is less noticeable when watching videos, but may be noticed on documents with white backgrounds. It is important to check reflections on an actual unit in store and determine an acceptable range.
Do they support waterproofing and Osaifu-Keitai mobile wallet?: Support varies by product. The Galaxy Z Fold6 and Pixel 9 Pro Fold support IPX8 waterproofing and Osaifu-Keitai. Dust resistance is weaker than slab-type devices, so care is needed when using them in dusty environments.
Which should I choose, flip-style or book-style?: Flip-style is suitable for portability priority, and book-style is suitable for working-area priority. Flip models are lightweight and less expensive, while book-style models are strong in split-screen display. It is advisable to compare weight and usability of the outer display and decide based on primary use.

Source: Singulism

Written by SINGULISM Editorial Team

Edited & reviewed by Kenichiro Yamamoto

If you find any factual errors or inaccuracies, we will promptly publish a correction. Please contact us via the contact form to request a correction.

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