Kerry Wan/ZDNET
Considering how much personal information we store on our smartphones, I wouldn’t be surprised if the demand for privacy screen protectors is at an all-time high. From bank statements to email credentials to photos and videos, the need to keep our digital footprint safe and secure, especially from the prying eyes of strangers, has never been more necessary.
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I gave the privacy-enhanced accessory a try, installing a variant from ESR on my Galaxy S25 Ultra. The installation process was the same as any other modern-day screen protector, with a guide tray that you set your Samsung phone into for near-perfect placement. The sheet of tempered glass lay centered on my phone, and the few air bubbles trapped beneath were easy to scrub off. Things were off to a great start.
Works as intended
The ESR screen protector worked exactly as intended: when staring at the S25 Ultra from the center, the display still looked bright, sharp, and vibrant. When I moved my head just a little bit to the left or right, the image quickly faded into black, as if the phone screen wasn’t turned on.
The two-way privacy filter worked like magic, and for the first time in a long time, I felt comfortable answering work emails and exchanging personal messages while on the New York City subway. Even if a stranger wanted to peek, they couldn’t.
But things took a turn
Things took a turn when I was catching up on Lakers highlights — and the display suddenly dimmed itself. Sure, my brightness setting is typically set to auto, but unless I’m moving between two drastically different lighting environments, which I wasn’t at the time, the shift in brightness should never be as dramatic as it was.
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My first assumption was that perhaps my shadow was cast over the phone’s light sensor, causing it to dim the screen. But that wasn’t the case. Instead, the tinting from the screen protector somehow caused the Android phone to think that the environment was darker than it actually was. This happened throughout my first day of testing, so I eventually surrendered to the physics of light and turned off the adaptive brightness setting.
The S25 Ultra, with a privacy screen protector installed, adaptively set the brightness to less than 50% when placed in front of a window.
Kerry Wan/ZDNET
The second issue with the privacy screen protector was that its thickness made it difficult to register fingerprints. When paired with the S25 Ultra’s ultrasonic fingerprint sensor, which uses 3D depth mapping to scan your finger, the phone often requested a more forceful press or a second attempt.
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I use the S25 Ultra’s ultrasonic fingerprint sensor more than the average person, as it’s essential for signing on to most of my personal services, Okta verifications for work apps, and, of course, unlocking the device.
Sure, re-registering my fingerprints helped improve accuracy and reliability to a degree, but not enough to make the experience of unlocking things burdenless. It got to the point where I relied more on the phone’s facial recognition to access things, which isn’t always efficient.
Going back to standard
That’s to say, I’ve since ditched the privacy screen protector in favor of a more standard, thinner plastic film. While I can’t be as secretive about my phone usage in public, I’ll take the scratch-resistant, viewer-friendly experience over that privilege every day of the week.
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This article was originally published on Feb. 3, 2025, and was updated on May 12, 2025.
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