Asus Zenfone 8 review: Just the right size

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Asus Zenfone 8 review: Just the right size
I’ve always had a thing for compact phones. My colleagues even invented a drinking game for every time I say “compact” during our daily meetings. That’s why when the enigmatic Asus invite for the Zenfone 8 announcement landed in my hands I knew I was in for a treat.

The Zenfone 8 is just the right size - it nails it perfectly. It’s not as small as an iPhone 12 mini, which some people find too small, and yet the phone is significantly more compact than your average modern flagship.

It’s not just the size, though. The Zenfone 8 packs a lot of features, especially considering its smile-inspiring price. The most powerful Qualcomm chipset - the Snapdragon 888 - lurks inside this little beast along with a gorgeous 5.9-inch 120Hz AMOLED panel made by Samsung.

It’s not always rainbows and butterflies, of course. The Zenfone 8 suffers from overheating issues when pushed to the limit and the 4,000 mAh battery feels a little underwhelming, especially in high-performance mode. Oh, and there’s no wireless charging and no micro SD card slot, too.

With all that being said, the Zenfone 8 offers a great overall experience, it’s fast, really comfortable to use, and won’t cost you a fortune. And that’s a great recipe if you ask me.


The best design feature of the Zenfone 8 is its size, obviously. The exact dimensions of the phone are 148 x 68.5 x 8.9 mm and to put these numbers into context I’d say that a guy with medium-sized hands (I’m 5’8” tall) can easily reach every corner of the display without any hand gymnastics involved.

The curved frosted glass on the back adds to the ergonomics - the phone feels great in the hand and it’s also pretty smudge-resistant. The display is flat with a 2.5D gorilla glass on top and a metal frame holds everything together.

The camera bump on the back is quite stylish and blends well with the overall design. Sadly, I can’t say the same about the punch-hole selfie cam in the top left corner. For some reason, there’s a silver ring around it that makes it pop up and not in a good way.

The sapphire blue power button on the right side of the frame is a nice touch, aesthetically pleasing and convenient. The left side of the phone is completely clean, there’s a 3.5mm audio jack at the top, and you get the usual stuff at the bottom - the SIM card tray, USB-C port, and the loudspeaker.

There are also a bunch of microphones around the frame doing their audio zoom and noise-reduction magic. Overall, the design of the Zenfone 8 won’t turn heads - it’s functional and understated.

That’s not a bad thing, though. Sometimes it’s good to see function over form - and also not get your hands obliterated by 90-degree phone frame angles (I’m looking at you, iPhone 12).


The 5.9-inch AMOLED display of the Zenfone 8 looks gorgeous. Asus doesn’t hide the fact that it’s a Samsung panel and that’s completely understandable - the Korean giant produces some of the best smartphone displays on the market.

Asus has gone wider with the aspect ratio - it’s 20:9, close to the 21:9 cinematic ratio that Sony uses in its Xperia lineup. The reason behind this is probably a pragmatic one - the wider aspect ratio allows for a more compact device while maintaining impressive diagonal numbers.

The resolution is FHD+ which translates to around 445 PPI, and it’s more than sufficient. The image is crisp and you’ll be hard-pressed to discern the individual pixels. Now, Asus boasts 800 nits of brightness on this device with a peak maximum of 1,100. While the latter may be hard to measure, the former claim holds as I was able to get 821 nits out of the Zenfone 8.

According to the specs, the E4 AMOLED panel sourced from SAMSUNG ensures color accuracy of 112% DCI-P3, 151.9% sRGB, 107.6% NTSC and Delta-E<1. Manufacturers use perfect-scenario settings to achieve these numbers and in reality, things are a bit different.

You can choose from several different color modes in the menu, and interestingly the Standard setting produces the most accurate colors (not the Natural, as one might think). Color temperature is also excellent in this mode, so I recommend using it, as Natural, Default, and Cinema modes tend to be cooler.

Another flagship-grade feature is the refresh rate of the display. The Zenfone 8 supports four modes - 60, 90, 120Hz, and Auto. Unsurprisingly, the 120Hz refresh rate mode feels the best on the eyes - everything is smooth and responsive (the 240Hz touch sampling rate and the 1ms response also help a lot).

All in all, there’s not much to complain about this AMOLED panel - it’s on par with every major (and also more expensive) flagship phone’s display out there. You also get lots of options in the menu such as DC Dimming (no flickering at low brightness levels), Smart screen, Always on, Lift-to-check, and more.

Camera & Audio

The Zenfone 8 sports a modest dual-camera setup on the back but don’t be fooled. Asus slapped some high-grade Sony sensors in there, so the results are quite pleasing. The main camera features a 1/1.7" Sony IMX686 64MP flagship sensor and has an F1.8 aperture. It has OIS and it’s capable of shooting 8K.24 fps videos as well.
The secondary ultra-wide camera uses a 1/2.55" Sony IMX363 12 MP sensor with an F2.2 aperture and 113˚ FOV, Dual PDAF. The selfie camera also features a Sony sensor underneath, it’s the IMX663 with Dual-PD autofocus - Asus claims it’s the fastest focus in a selfie camera.

In good lighting conditions, the main camera takes 64MP photos and they look really good. Lots of details are present even when the light comes at tricky angles. The colors seem to be a little exaggerated, which might please some people and annoy others.

Low-light photography relies on the Quad Bayer filter trick, taking 12MP photos with better light sensitivity. In reality, the Night Mode only works when there’s some light present and it’s quite situational. Your results may vary - from stunning detail-revealing night shots to a dark and messy blur.

It’s worth noting that there’s a small color shift when switching between the two sensors with the ultra-wide camera producing blueish and cooler images. The selfie camera is really good, all the claims for fast focus and detailed images hold true.

I was really impressed with the Hyper Steady mode during the video sample recording. It obviously crops the image and this mode is only available in FHD resolution but still, it’s quite impressive. The Zenfone 8 can shoot videos with a resolution of up to 8K but for all practical purposes, you’ll be fine with 4K/60fps.

Video Thumbnail
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The overall audio experience is also great with the Zenfone 8. The phone features stereo speakers, which is great considering its size. The sound is surprisingly loud and clear for such a small device. For you audiophiles out there, the Zenfone 8 retains the 3.5mm audio jack and on top of that, it comes equipped with the latest Qualcomm Aqstic WCD9385 DAC.

The phone supports hi-res audio files rated at up to 32-bit 384 kHz and you can plug a pair of pro-grade headphones and enjoy. The Audio Wizard software completes the experience with a 10-band equalizer and different “styles”, tuned by Dirac.

I tested all this with my trusty Audio-Technica ATH-M50xBT both wired and in Bluetooth mode, and the results were very pleasing to the ear. Whether or not you care for your audio, having this setup available is a great bonus to Zenfone 8’s overall package.

Software & Performance

The other big selling point of the Asus Zenfone 8 is its chipset. At 599 Euro starting price, it’s one of the most affordable Snapdragon 888 phones on the market. If you take a quick scan through the benchmark scores you’ll see that it’s a beast of a phone.

Cramming this top-of-the-line processor in such a small chassis has its downsides, though. When you really put the Zenfone 8 through its paces, the phone gets really hot, to the point where it’s painful to hold.

This happens only during synthetic benchmarks (the phone automatically switches to High-Performance mode when it detects those) but it’s something worth noting. It’s also worth noting that the performance score takes a 10-15% hit when the phone starts to overheat.

In day-to-day use, the Zenfone 8 feels like a 2021 flagship - fast, responsive, and overall a joy to use. The under-display fingerprint sensor is one of the fastest I’ve ever tested (normally, I prefer side-mounted capacitive ones), games play smoothly without any stutter, apps open and close fast.

The Zenfone 8 runs on Android 11 with the ZenUI8 on top, and it’s a pleasant experience. The custom user interface is really close to stock Android with some nice additions - such as the Animation speed of the interface - an option that’s not easily accessible on a normal Android and an option that can make your phone feel faster than it really is (although with an SD888 chipset that might not be necessary).

Gamers and alike will be pleased to find the Game Genie software making an appearance in the Zenfone 8, proving that you don’t need a ROG phone to game competitively. Sadly, the SD card slot is gone, in line with the latest trends but the phone comes in different memory configurations - 6/128, 8/128, 8/256, 16/256GB.

Higher is better
Asus ZenFone 8
Apple iPhone 12 mini
OnePlus 9
Samsung Galaxy S21
Google Pixel 5
Sony Xperia 5 II

Battery life

The Zenfone 8 packs a 4,000mAh battery and while this size is okay-ish in bigger phones, it’s impressive in a sub-6 inch device. Your mileage will vary depending on a great many things. There’s a super-comprehensive battery control center and you can literally spend hours fiddling with the settings.

Of course, if you don’t have the time, there are four main presets to choose from - High Performance, Dynamic, Durable, and Ultra Durable. They’re self-explanatory more or less and for the best blend of performance and longevity, you should leave the phone in Dynamic mode.

The Zenfone 8 performed really well in our browsing test, and even if you want everything 120Hz-smooth, you can get a solid 10 hours of browsing time. Which is quite impressive, to be honest. Gaming in 120Hz drains the battery fairly quickly, and if you decide to stick to 60Hz you can add up to 2 hours of playtime.

The Zenfone 8 comes with a 30W fast charger in the box, and it can charge the 4,000 mAh battery from 0 to 100% in around 90 minutes. There are a couple of options regarding how you want to charge your phone in the aforementioned battery control center app. You can set a charge limit, schedule your charging time, and even limit the power that goes to the battery in order to lower the temperature and increase its longevity.

Browsing test 60HzHigher is betterBrowsing test 120Hz(hours)Higher is betterVideo Streaming(hours)Higher is better3D Gaming 60Hz(hours)Higher is better3D Gaming 120Hz(hours)Higher is betterCharging time(hours)Lower is better
Asus ZenFone 812h 33 min
10h 12 min
11h 23 min
8h 42 min
6h 38 min
1h 27 min
Apple iPhone 12 mini10h 56 min
No data
5h 10 min
5h 10 min
No data
1h 35 min
OnePlus 911h 45 min
11h 29 min
9h 16 min
9h 6 min
No data
0h 30 min
Samsung Galaxy S219h 6 min
7h 47 min
7h 36 min
7h 9 min
4h 14 min
1h 10 min
Google Pixel 512h 40 min
No data
8h 49 min
6h 51 min
No data
1h 33 min
Sony Xperia 5 II13h 38 min
9h 39 min
9h 8 min
5h 43 min
4h 45 min

Best Asus Zenfone 8 alternatives

There aren’t many alternatives to the Zenfone 8 and Asus knows it. The phone occupies a niche many people considered long gone - the compact and affordable flagship. In a reality where screen estate is king, launching a 5.9-inch flagship is a bold move. Especially considering the sales figures of the iPhone 12 mini.

The Samsung Galaxy S10e is now ancient history and you should consider the S21 as the closest Zenfone 8 competitor. The Samsung flagship comes with an equally good display, wireless charging, a great camera system, and it’s almost as compact as the Asus. If you’re willing to do some deal-hunting you can probably get the S21 at around the same price, too.

Samsung Galaxy S21

- with activation
$649 99
$799 99
Buy at BestBuy

There’s always the Xperia 5 series. The big downside is that Xperia phones are quite expensive and they tend to retain their high prices over time. Even though the Xperia 5 III is just around the corner, the older Xperia 5 and 5 II still cost a hefty $700-800. Still, if you want that narrow, tall experience, and you’re willing to pay extra for the Sony geekiness, you can absolutely go for an Xperia device.

Sony Xperia 5 II Unlocked Smartphone

What about the OnePlus 9? It’s arguably a better phone but it’s also bigger and more expensive. Is it worth it? It depends. Asus is aiming to deliver the best performance in the smallest and most affordable package and it’s hard to beat the result.

OnePlus 9 Pro

- 12GB + 256GB storage
Buy at OnePlus

OnePlus 9

$499 99
$599 99

I almost forgot about Pixel phones of late. The Pixel 4a is even more compact and also cheaper, but it’s underpowered and not a flagship per se. You can probably get a Pixel 5 for nearly the same price but again, it’s not the flagship experience you’ll be getting with the Zenfone 8.

Google Pixel 5

128GB, Just Black or Sorta Sage, 90Hz display, Snapdragon 765G
$724 99
Buy at AT&T

Google Pixel 4a 5G

128GB, Just Black, Snapdragon 765G
$524 99
Buy at AT&T

And finally, we come to the iPhone 12 Mini, of course. Is it the Zenfone 8’s only real competitor? I don’t think so. It’s smaller and probably easier to operate (although those hard edges really hurt your hand) but it’s also more expensive and the battery life is underwhelming, to say the least. The iPhone 12 Mini is also an iOS device (duh, obviously) and people don’t change sides all that often.

Apple iPhone 12 mini

Get $25-$600 off with eligible trade-in.

With the Zenfone 8, Asus has found a sweet spot in the market space. It can turn sour really fast, though, as people might not buy into the compact idea all over again.


  • Compact and easy to handle
  • Top-level performance
  • Great display
  • Cameras are pretty good
  • Good battery life, especially for the size
  • Stereo speakers, 3.5mm audio jack, hi-res audio support
  • Clean and feature-rich UI
  • Competitive price tag
  • IP68 water and dust resistance


  • Gets hot in high-demanding situations
  • No wireless charging
  • No SD card slot
  • The small size might be a con for some people

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