Asus ZenBook S UX391UA Review

Laptop Mag Verdict

The Asus ZenBook S' gorgeous 4K display, innovative design and elegant chassis make it well worth its reasonable price.


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    Vivid 4K display

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    Innovative hinge

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    Comfortable keyboard

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    Thin and lightweight design

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    Competitive price


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    Below-average battery life

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    Runs warm

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Editor's Note: We updated certain sections like Display and Battery Life with results from the 1080p configuration of the ZenBook S.

The clamshell laptop design hasn't changed much over the years, which is why I was cautiously optimistic when the Asus ZenBook S landed on my desk. The Ultrabook's elevated hinge is truly unique, and makes the laptop's keyboard a pleasure to type on. But what really stands out about the ZenBook S (starting at $1,199, $1,499 as tested) is its gorgeous display and remarkably thin and lightweight design. Despite having below-average battery life, the ZenBook S is one of the best premium laptops for your money.


The Asus ZenBook S is the definition of chic.

Its dark-blue aluminum finish trimmed with rose gold is elegant rather than gaudy. The ZenBook S is so stylish, it wouldn't be out of place in an exorbitantly priced Louis Vuitton bag.

On the lid is a gold Asus logo in the center of the company's signature texture of concentric circles. Under the lid is a sparkling blue deck and a keyboard with gold text. It's worth noting that the lid and deck looked black in our dim office, and I could make out shades of blue only in direct sunlight. With the display, Asus struck the perfect balance of aesthetics and practicality. Although the bezels are narrow, there's still enough space above the screen for a webcam. 

The ZenBook S belongs in an office environment as much as it does in an exorbitantly priced Louis Vuitton bag.

The ZenBook S' elevated hinge is even more striking than the laptop's gorgeous looks. The lid wraps around to the bottom of the chassis, so when the laptop is opened, the back edge rotates below the deck, elevating it off the ground.

With the back of the deck raised, the keyboard tilts upward at a 5.5-degree angle. According to Asus, the design offers three benefits: a more comfortable typing experience, better heat management and improved sound quality. Unfortunately, the ZenBook S didn't meet all of these claims in our testing. One drawback with the hinge is that a large gap forms between the deck and the display, forming a sanctuary for dust and dirt. 

MORE: Ports Guide

The hinge felt sturdy in our testing and the display wobbled only slightly when I tapped hard on the touch screen. While its unique design may suggest the ZenBook S is a convertible 2-in-1, the lid folds back 145 degrees.

The ZenBook S is remarkably compact and lightweight. It's so small that my colleague glanced at it and assumed it was a 12-inch laptop. At 12.2 x 8.4 x 0.5 inches, the ZenBook S is thinner but wider than the 13-inch MacBook Pro (12 x 8.4 x 0.6 inches) and the Huawei MateBook X Pro (12 x 8.5 x 0.6 inches). The Dell XPS 13 is even more compact at 12 x 7.9 x 0.5 inches. Incredibly, the ZenBook S weighs less than its competitors at 2.4 pounds.


As expected for a system so slim, the ZenBook S is short on ports. On the right side are two Thunderbolt 3 connections for charging, fast data transfer, and connecting to displays or graphics docks.

On the left side is a single USB 3.1 Type-C port and LED indicators for battery life and power. The laptop comes with a matching carrying sleeve, a USB-C-to-USB-A dongle, and a USB-C-to-HDMI cable.


The 3,840 x 2,160-pixel display on the ZenBook S is brilliant, although it's not quite as gorgeous as other top panels we've tested. When I watched a 1080p trailer of the upcoming Predator film, I could see individual strands of hair in Boyd Holbrook's beard, and the clarity of the extraterrestrial intruder made it especially terrifying.

I was blown away by the display's vibrancy. When I watched a trailer for the upcoming spy comedy, Johnny English Strikes Again, the glossy red paint on Rowan Atkinson's classy Aston Martin was richly saturated. At a bar scene, Atkinson's light blue suit popped against the contrasting yellow lights of the posh venue. White balance is also excellent, and the display's vivid colors jumped off the clean background of my favorite news sites.

The ZenBook S display did well in our lab tests, but it was outperformed by competing laptops. Asus' notebook can reproduce 116.4 percent of the sRGB color gamut, which is above the premium laptop category average (111 percent). However, the 4K Dell XPS 13 (130 percent), the Huawei MateBook X Pro (124 percent) and the 2018 13-inch Apple MacBook Pro (119 percent) were more colorful. The ZenBook S' 1080p panel covered 115.7 percent.

When I watched a 1080p trailer of the upcoming Predator film, I could see individual strands of hair in Boyd Holbrook's beard, and the clarity of the extraterrestrial intruder made it especially terrifying.

The ZenBook S reached a maximum brightness of 323 nits (274 nits on 1080p). Again, that beats the premium laptop category average (306 nits) but falls short of the 4K Dell XPS 13 (415 nits), the Huawei MateBook X Pro (458 nits) and the Apple MacBook Pro (439 nits).

MORE: Laptop Screen Guide: Resolution, Refresh Rate, Color and Brightness

The ZenBook S' touch-sensitive panel is responsive and fluid. I had no issues browsing the web by tapping and swiping my fingers on the glass. Unfortunately, the ZenBook S' reflective screen made its gorgeous picture difficult to see in our dimly lit office.


The Asus ZenBook S' speakers sound good, but they don't get very loud. The laptop struggled to fill a large conference room when I played St. Vincent's "New York," but Anne Erin Clark's distinct vocals sounded crisp and clear. Death Cab For Cutie's atmospheric new single, "I Dreamt We Spoke Again," sounded lively, with ample slam to the drums. There was even a light bass thump when I listened to Drake's "In My Feelings." As expected from a laptop this small, the sound wasn't full, but I wouldn't consider it hollow, either.

Keyboard and Touchpad

The angled keyboard on the ZenBook S felt more comfortable than the traditional flat keyboards I've used. My wrists were in a relaxed position, thanks to its gentle upward tilt. The keys remind me of those on the MacBook Pro, but better.

An ideal actuation force of 70 grams made up for the ZenBook S' low 0.9 millimeter key travel (our recommended range is 1.5 mm to 2 mm). Better yet, the keys are clicky, and the backlighting has adjustable brightness levels, which is not something we typically see on non-gaming laptops. Also, the keys are well-spaced (though a few are undersized).

MORE: Hey, Apple: Fix Your Crappy Keyboards or I'm Switching to Windows

Because the deck is compact and Asus' palm rejection isn't perfect, my hand annoyingly moved the cursor as I typed. I found myself occasionally lifting my palms off the touchpad to prevent this problem.

The angled keyboard on the ZenBook S feels more comfortable than traditional flat keyboards like the MacBook Pro's.

I achieved 115 words per minute at an accuracy of 96 percent in the typing test. That's quicker than my typical 109 wpm average and a bit better than my average accuracy of 95 percent.

The ZenBook S' smooth touchpad is responsive. I didn't have any problems executing numerous gestures, like scroll, pinch-to-zoom, or three-finger swipes to see all open windows. The touchpad has a built-in fingerprint sensor on the top-right corner.


Equipped with an Intel Core i7-8550U, 16GB of RAM and a 512GB SSD, the ZenBook S has plenty of power to run demanding programs or high-resolution videos. I noticed only slight lag when loading 21 Google Chrome tabs, two of which played 1080p YouTube videos and one that ran a 1080p Twitch stream. I then added a 4K-resolution YouTube video to the workload to see if I could stump the Ultrabook, but it booted up the clip without hesitation.  

The ZenBook S scored 11,611 on the Geekbench 4 test, which determines the general performance of a laptop. That beats the premium laptop average (11,052) but loses to top competitors, like the Dell XPS 13 (14,180), the Huawei MateBook X Pro (12,913) and the Apple MacBook Pro (17,572).

The 512GB PCle SSD in the ZenBook S duplicated 4.97GB of mixed-media files in 16 seconds for a rate of 318 megabytes per second. The ZenBook S outpaced the Huawei MateBook X Pro (283 MBps) but couldn't catch up to the XPS 15 (508 MBps). The 2018 MacBook Pro has the Usain Bolt of hard drives, which reached an astounding write speed of 2,682 MBps. We also tested the 256GB SSD version, and that produced a rate of 121 MBps.

The ZenBook S was a bit sluggish in our Excel Macro stress test, which involves matching 65,000 names with their corresponding addresses. It completed the task in 1 minute and 51 seconds, which is slower than the Dell XPS 13 (1:08), the Huawei MateBook X Pro (1:49) and the Apple MacBook Pro (1:17). The premium laptop average of 1:34 is also quicker.

The ZenBook S' worst results came in our video-transcoding test, where we use Handbrake to convert a clip from 4K to 1080p resolution. The ZenBook S completed the test in a leisurely 37 minutes and 51 seconds, which is significantly slower than the premium laptop average (22:15). The Dell XPS 13 (16:00), the Huawei MateBook X Pro (27:18) and the Apple MacBook Pro (16:57) trounced the ZenBook S.


The ZenBook S isn't meant for gaming, but it can play less-demanding titles at low settings. The system's integrated Intel UHD Graphics 620 GPU scored a 80,332 on the Ice Storm Unlimited graphics test. That figure falls just short of the premium laptop average (83,517) and the scores earned by the Dell XPS 13 (85,616) and the Huawei MateBook X Pro (116,359).

The ZenBook S didn't fare any better in real-world tests. It played Dirt 3 at 1080p resolution at 45 frames per second. Although that surpasses our playability threshold of 30 fps, it falls below the Huawei MateBook X Pro (117 fps), the Dell XPS 13 (67 fps) and the MacBook Pro (47 fps). The category average is a smooth 69 fps.

Battery Life

The Asus ZenBook S' battery life is below average. It lasted 7 hours and 5 minutes on the Laptop Battery Test, which involves continuous web surfing over Wi-Fi at 150 nits of brightness. Other premium laptops had longer runtimes, including the 14-inch Huawei Mate X Pro (9:55), the 4K version of the Dell XPS 13 (8:23) and the MacBook Pro (8:23). The premium laptop battery life average is 8:20, but the 1080p ZenBook S managed to surpass that, at 09:26.

MORE: Laptops with the Longest Battery Life


The ZenBook S' elevated hinge failed to adequately improve airflow in our testing. The notebook's underside reached 107 degrees Fahrenheit, and the location between the G and H keys warmed to 101 degrees when we played a 15-minute video at 1080p resolution. The bottom lower-left side was the hottest location on the laptop, reaching 111 degrees, which exceeds our 95 degree comfort threshold. Only the touchpad stayed cool at 87 degrees.


The ZenBook S' 720p webcam is solid. It captured a bright, well-exposed image in our dimly lit office, and its white balance and color reproduction were on point. The dark-red color in my shirt was true, and my light skin tone was accurately captured. For how bright the shot was, there was far too much visual noise, and details appeared blurry.

Software and Warranty

The ZenBook S' Windows 10 Home OS comes pre-installed with an Asus folder filled with apps. Among the more useful programs are Asus Live Update, which installs the latest drivers on your machine, and Asus Splendid, which allows you to change the color temperature of your display. There is also a Quiet Fan app, but we'd keep the default "high-performance" setting turned on considering how hot the ZenBook got in our testing. McAfee WebAdviser also makes an unwelcome return.

The rest of the bloatware installed on the ZenBook S comes courtesy of Microsoft, including Netflix and LinkedIn apps.

The Asus ZenBook S comes with a one-year warranty. See how the company performed on our Tech Support Showdown and Best and Worst Brands ranking.

Asus ZenBook S Cost and Configurations

For $1,499, the 4K unit I reviewed came equipped with an Intel Core i7-8550U processor, 16GB of RAM and a 512GB SSD. Another version with the same processor but 8GB of RAM and a 256GB SSD costs $1,199. The Asus ZenBook S is available in Deep Dive Blue (dark blue) and Burgundy Red. 

MORE: What are the Best Asus Laptops?

Bottom Line

The Asus ZenBook S is an extremely lightweight laptop with a gorgeous, premium design and a vivid 4K display. It has strong performance, although it doesn't stack up well against other premium laptops, like the Dell XPS 13 and 13-inch MacBook Pro. But those laptops don't have the ZenBook S' hinge, which makes its keyboard significantly more comfortable to type on.

The Asus ZenBook S is priced to sell at $1,499 for a Core i7 CPU, 16GB of RAM and a 512GB SSD. That puts it up against the 14-inch Huawei MateBook X Pro. Although the ZenBook S is lighter and sleeker, we prefer the MateBook X Pro for its longer battery life, snappier keyboard and wider variety of ports.

We also suggest you consider the XPS 13. It has better performance and longer battery life than the ZenBook S, but you'll need to throw down $1,999 for comparable specs. That makes the ZenBook S an excellent value for anyone in the market for a premium laptop.

Image credit: Laptop Mag

Asus ZenBook S UX391UA Specs

BluetoothBluetooth 4.2
CPUIntel Core i7-8550U
Company Website
Display Size13.3
Graphics CardIntel UHD Graphics 620
Hard Drive Size512GB
Hard Drive TypeNVMe SSD
Highest Available Resolution3840 x 2160
Native Resolution3840 x 2160
Operating SystemWindows 10 Home
Ports (excluding USB)USB 3.1 with Type-C, Thunderbolt 3, Combo Headphone/Mic Jack
Size12.24 x 8.39 x 0.51 inches
Touchpad Size4.1 x 2.4
USB Ports3
Warranty/Support1-year limited warranty.
Weight2.42 pounds
Wi-Fi ModelIntel Wireless AC-8265
Phillip Tracy

Phillip Tracy is the assistant managing editor at Laptop Mag where he reviews laptops, phones and other gadgets while covering the latest industry news. After graduating with a journalism degree from the University of Texas at Austin, Phillip became a tech reporter at the Daily Dot. There, he wrote reviews for a range of gadgets and covered everything from social media trends to cybersecurity. Prior to that, he wrote for RCR Wireless News covering 5G and IoT. When he's not tinkering with devices, you can find Phillip playing video games, reading, traveling or watching soccer.