携帯電話用のプライバシースクリーンプロテクター: その仕組みと、ご自身にとって最適な製品の選び方。

Your mobile phone holds more sensitive information on you than some of your closest friends. Alas, our mobile phone can always be found in our hands, purse or pockets -- we quite literally cannot leave home without it. And with no time to waste, we’re also frequently maximizing every spare moment in our day, meaning sensitive information is being handled in plain sight while we’re out and about. It’s easy to see why securing your personal information is a top concern when prying eyes can simply glance over an unsuspecting shoulder and gather critical intel.

• Passwords
• Photos
• Banking information
• Notes
• Confidential business emails
• Personal text messages/emails
• Locations - of yourself and loved ones

...and more. A simple fix is the use of a privacy screen protector for your mobile phone.

For at-home applications:

• At-home application kits typically include tools to help the process along, including a tray, dust removal sticker, microfiber cloth, an object to smooth out air bubbles and more. Most importantly, you must ensure your hands are freshly cleaned before starting the process to avoid fingerprints (latex gloves are also a good option), and that your screen is clean and dust free before applying the protector. When the tools are used correctly, you can achieve a bubble-free, high-quality application at home.

For in-store applications:

• When purchasing a privacy screen protector in-store, some retail locations may offer a trained sales professional to help apply it for you. 

Gently lift the corner edge of the screen protector and peel it up and away. If you plan to reuse the surface, keep the protector clean and store it face-down on its backing.

Quality is an important factor when it comes to screen protection, as not all are made the same. It’s common to find that some lesser-quality privacy screen protectors cause a Moiré effect (when two patterns with similar frequencies interact with each other). This creates visible lines on the screen that can make you feel dizzy and nauseous, typically due to the privacy screen protector not being tested on an actual screen in production.

Another issue with lesser-quality products is that they work by simply darkening the screen without using any specialized technology. This makes the screen more difficult to see overall, even for the one who is meant to be viewing it. When utilizing optimal technology, some privacy screen protectors can provide additional benefits such as minimizing the emission of harmful blue light.

Yes. Privacy screen protection can be found across various devices with screens, not just mobile phones.

Yes. However, this depends on the material and quality of the screen protector itself. Like traditional screen protection, privacy screen protection is available in both film (plastic) and glass versions, with different levels of protection, depending on the material and manufacturer. The best protection is made of strong, tempered glass, to maintain the look, feel and performance of your phone’s screen while protecting it from microbes, scratches and impact.

Generally, security screens can make the display appear slightly darker or less vibrant. This is due to the privacy technology, which is specially designed to block the view from certain angles. Utilizing advanced screen protection technology should maintain the screen’s visual quality even with privacy factors in place. In comparison, lesser quality screen protection may cause the display to appear grainy or pixelated, due to the use of patterned films used to block the viewing angles. If you feel your screen has reduced slightly in brightness with the privacy overlay applied, you can turn up the brightness settings on your device.

When selecting a privacy screen protector, look for a combination of high-quality, high-impact screen protection and authentic, genuine privacy technology that works to distort your mobile phone’s screen from onlookers without compromising the integrity of its visual quality. After all, mobile phones are an investment, and a little protection goes a long way.

For the iPhone 17, iPhone 17 Pro, and iPhone 17 Pro Max, Belkin's InvisiGlass Privacy Filter adds a two-way privacy filter over tempered glass, so the screen looks dark from the sides while staying clear for you. It is cut for the exact model, including the sensor and Face ID cutouts. Browse every size in the iPhone 17 screen protectors collection.

Yes. The UltraGlass 2 Privacy line fits iPhone 16 and iPhone 15, with model-specific versions so the fit is exact, including the iPhone 16 Pro Max size. See the full iPhone 16 screen protectors collection.

Yes. Privacy filters use the same micro-louver technology on any phone, and Belkin makes model-specific options beyond iPhone, including for Samsung Galaxy. Browse them on the Samsung screen protectors page.

If you handle passwords, banking, messages, or work documents in public, a privacy filter is a low-cost way to block shoulder surfing and visual hacking. Our screen protector buying guide walks through the trade-offs so you can decide.