ASUS Zenfone 9 Review – 169g, 5.9″ Lightweight Compact with High Performance

Zenfone 9

Rating: 5

I was loaned the ASUS Zenfone 9.

Lightweight, compact and high performance

The ASUS Zenfone 9 is a smartphone powered by Snapdragon 8+ Gen 1.

While smartphones these days are becoming larger and larger, the Zenfone 9 has a small 5.9″ display and weighs only about 169g.

Since high-end smartphones often exceed 200g as a matter of course, Zenfone 9 is perfect for those who want a compact and light smartphone.

The disadvantages of a compact smartphone, such as low performance and a tendency to generate heat, are also solved thanks to the Snapdragon 8+ Gen 1 and the heat dissipation design.

This review is done with version WW_AI2202_32.2050.2050.29, 16GB+256GB version.

  • Lightweight at approximately 170g
  • Compact size of 5.9 inches
  • High performance and efficient Snapdragon 8+ Gen 1
  • AMOLED with 120Hz refresh rate support
  • 3.5mm earphone jack available
  • Low touch latency of 37.5ms
  • IP68 water and dust resistance
  • In-camera is reflective and easily noticeable
  • Black color makes it easy to see dirt on the back
ASUS Zenfone 9 AI2202
OS Android 12
 Storage 128GB / 256GB UFS 3.1
SoC Snapdragon 8+ Gen 1
Display 5.9inch
FHD+ 2400 x 1080
Aspect Ratio 20:9
 Size 146.5 × 68.1mm × 9.1mm
 Weight 169g
SIM nano SIM + nano SIM
Rear Camera 50MP (OIS・SONY IMX766)
+ 12MP (Ultra-wide SONY IMX663)
 Front Camera 16MP (SONY IMX663)
Battery 4300mAh
USB Port USB Type-C (USB 2.0)

Zenfone 9

Many recent products do not come with a charger, but Zenfone 9 comes with a charger that supports 30W fast charging and a USB Type-C to C cable.

It also comes with a hard-type protective case, which protects the back of the case while retaining a better appearance than the transparent soft type.


Compact yet bright and vivid display

The Zenfone 9 has a 5.9-inch, AMOLED display with FHD+ resolution.

The in-camera is located in the upper left corner.

The edge is silvery rather than black, which makes it easily noticeable in light reflections.

The durable Corning Gorilla Glass Victus is used.


It is made by Samsung and is a diamond pixel array.

It is brilliant, beautiful, and has good viewing angles.


When measuring brightness with the LX-1336B during HDR video playback with automatic brightness adjustment on, the maximum reached 694 nits.

When in high brightness mode with automatic brightness adjustment on and displaying still images, the maximum brightness reached 758 nits. It is quite bright and easy enough to see outdoors.


The total touch latency measured by the WALT Latency Timer was 37.5ms.

This is a great low touch latency, on par with gaming smartphones such as the REDMAGIC 7S.

This is good news for those who have been using unavoidably heavy smartphones for gaming because they can enjoy games with low touch latency even without a large smartphone.


Widevine L1 allows streaming in HD quality on Amazon Prime Video (beta) and others.

Widevine L1

Matte back

The back of the Zenfone 9 has a matte finish and is fingerprint resistant.

However, it seems to be vulnerable to rubbing, and there were whitish scratches left behind that would have been caused by media borrowed before mine.

If you are concerned about scratches, it is better to use the hard cover that comes with the product.


It weighed 170.1 grams.

It is lightweight for a recent smartphone, and its lightness and size make it easy to hold in one hand.


Shake-resistant dual camera with gimbal

Zenfone 9 has a dual 50MP (OIS / SONY IMX766) + 12MP (Ultra-wide SONY IMX663) camera.

While the IMX766 is not a good enough sensor for a high-end smartphone, it is a compact smartphone.

Instead, it has a 6-axis hybrid gimbal stabilizer, which makes it more resistant to camera shake than phones with only electronic image stabilization.

Zenfone 9

All photos were taken hand-held and are stored here.

Saturation is not too high and the difference between red and magenta is relatively easy to see.


If you zoom in, you can see that details have been smashed, but the picture is beautiful enough.


Even in night scenes, the light source is not blown out and the surroundings are well-lit.

The camera is also equipped with a light trail mode, which allows you to take pictures in which lines of light appear to be connected.


The 6-axis hybrid gimbal stabilizer can be used not only for video but also for photography, and the stabilizer guide can be used to keep track of any tilting.

When I went down a hill on a short run with image stabilization enabled, the camera actually shook quite a bit, but in the video it appears as if there was almost no shaking.

Stereo speakers with earphone jack

The Zenfone 9 has stereo speakers of the type used for calls.

The bottom speaker is slightly louder and richer sounding.

Both bass and treble sounds are clear. The back of the device vibrated in situations with strong bass.

It is DIRAC-compatible, and bass and treble can be adjusted with the sound mode and equalizer.

USB Type-C

There is an earphone jack on the top.

While many smartphones are discontinuing it these days, it is nice to be able to use wired earphones without a conversion adapter.

Snapdragon Sound is also supported, so you can enjoy high-quality music even with wireless earphones.


This is useful during gameplay, for example, as it provides lower latency than fully wireless earbuds.


The WALT Latency Timer measured the audio output delay of the earphone jack to be 36.9 ms.


Smart key with built-in fingerprint sensor

On the right side are the volume and power buttons.

The power button has a built-in fingerprint sensor and can be used as a smart key for various operations other than fingerprint recognition.


By sliding up and down, you can view notifications and move to the beginning or end of a page.

This is a simple but quite useful feature.


You can also press twice or press and hold to activate the app.


There is nothing on the left side.


Compact yet high-performance & power-saving

Compact smartphones have difficulty dissipating heat and often perform worse than larger phones.

The Zenfone 9 boasts high performance and power-saving performance that can even beat gaming smartphones thanks to the combination of Snapdragon 8+ Gen 1 and a cooling system that uses copper heat spreaders and vapor chambers.

High performance mode is automatically turned on when benchmark apps are detected, but since it is important to measure performance in everyday use, we reverted to dynamic mode for our measurements.


In Geekbench 5, the Genshin disguised version scored 1298 single-core and 3886 multi-core, the normal version scored 1180 single-core and 3670 multi-core, and the high-performance mode scored 1300 single-core and 4353 multi-core.

The scores are slightly higher for the Genshin disguised version than for the normal version, so it may be that the thermal control is relaxed for higher performance with Genshin.

The high performance mode has a much higher multi-core score in particular, exceeding all gaming smartphones I have measured in the past.


In the 3DMark Wild Life Stress Test, the score was 10286, with a temperature rise from 22°C to 37°C (15°C increase) and battery consumption of 11%.

The stability was 53.3%, and it seems that the dynamic mode is adjusted mainly to suppress the temperature rise.

Anyway, it is good to be able to use the high performance mode for games when peak performance should be higher, and the dynamic mode for everyday use when it is less likely to get hot.


PCMark Work 3.0, which measures performance in everyday use such as document manipulation, scored 14674.


Storage is fast there, and memory speed is among the fastest of the LPDDR5 memory-equipped models.


When playing Genshin at the highest quality and 60FPS setting and measuring with WeTest PerfDog, the average was 57.0FPS and 105.71mW power consumption per FPS.

Since the ROG Phone 6, a gaming smartphone, had 59.3 FPS and 112.38 mW, we can see that Zenfone 9 is able to achieve both high performance and power savings despite its compact size.

The battery temperature was around 41°C at maximum, and the side frame was quite hot, but not so hot that it could not be touched.


When playing World of Tanks Blitz at 120FPS and the highest graphics settings, the average FPS was 119.6, with a power consumption of 34.88mW per FPS.

This top-class power-saving performance, despite the fact that it is almost always running at 120 FPS, allows the user to continue playing with smooth motion for a long period of time.



  • Lightweight at approximately 170g
  • Compact size of 5.9 inches
  • High performance and efficient Snapdragon 8+ Gen 1
  • AMOLED with 120Hz refresh rate support
  • 3.5mm earphone jack available
  • Low touch latency of 37.5ms
  • IP68 water and dust resistance
  • In-camera is reflective and easily noticeable
  • Black color makes it easy to see dirt on the back


The ASUS Zenfone 9 boasts such high performance that it can play Genshin at an average of 57.0 FPS while keeping it to a compact size that is easy to hold in one hand.

The synergy of the power-saving Snapdragon 8+ Gen 1 and heat suppression tuning results in considerably less heat generation in everyday use, and the battery life of 4300mAh, less than that of other large smartphones, is not a concern.

ZenUI is also quite easy to use, with gesture controls, volume controls, and other itchy multifunctionality, while the overall design is similar to AOSP.

The Zenfone 9 is recommended for those who do not want to use a phone that weighs over 200g and want a small phone that can be used easily.

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