Asus ZenFone 2 review; the true flagship killer

8.8 Above Average

The Asus ZenFone 2 is power-packed to go head to head with any device on the market. The only holding it back is its lack of major updates (still running Android 5.0 Lollipop) and amount of pre-installed bloatware. For $300, it is the best bang for the buck on the market.

  • Design 8.9
  • Display 8
  • Performance 9.4
  • Camera 8
  • Battery 9.5
  • User Ratings (2 Votes) 9.5

All the way back at CES 2015, Asus announced their next generation of flagship phones. Among them was the Asus ZenFone 2, a power-packed smartphone that comes unlocked for under $300. Inside device comes an Intel Atom 64-bit processor clocked 2.3 GHz. Backing the processor is a whopping 4 GB of RAM, the first of any smartphone. That’s why the $300 price-tag was so astonishing. Not only that, but the phone has 64 GB of internal storage and the ability to expand.

Not only does the Asus ZenFone 2 boast some of the best hardware of 2015, it also has a 5 megapixel front-facing camera with a 13 megapixel rear-facing camera. If this design model sounds familiar, picture it as a direct competitor to the OnePlus One as it features the same size 5.5 inch FHD display and a 3,000 mAh battery.

If a phone is packing an Intel Atom processor and 4 GB of RAM, there has to be a catch, right? Well, let’s take a look at the Asus ZenFone 2 and see how it handles.


You would think with a lower price tag for a device, the options available would be slim to none. With the ZenFone 2, there are a multitude of colors available: Silver, Black, Gold, and Red. We got our hands on a Silver model.

The Asus ZenFone is packing a 5.5 inch display, so it is quite larger, especially to allow for capacitive navigation buttons. The overall dimensions of the device are 152.5 x 77.2 x 10.9 and tips the scales at 170 grams . The reason for the extra thickness, aside from packing dual-SIM slots, microSD slot, and a 3.000 mAh battery, is that Asus decided to give the device a very ergonomic feel.

Asus ZenFone 2 removable battery cover

The design is headed in the direction of the LG G3 and Nexus 6. The devices have curved backs to make holding the phone very comfortable, especially for extended periods of time. Not only does it feature a design similar to the G3, but it also features rear-facing volume buttons.

Where it differs is the location of the power button. The power button is on top of the device in the middle. At first I thought it would be slightly uncomfortable to unlock and lock the device using the power button, but it actually was the opposite. Once you get used to it, it isn’t in a bad spot at all, especially the way larger phones are held these days. It isn’t my first location choice, but it keeps the sides button free and convenient to hold.


Like I mentioned earlier, the device is quite tall for a 5.5 inch device due to the use of capacitive navigation keys below the display. It equates to around a 3 mm difference, so not huge, but it is noticeable. The device does also have larger than usually side bezels, but it is also negligible. To compare it to the OnePlus One, it is 1.3 mm wider overall, and .65 mm wider on either side of the screen.

Since the volume buttons and power button are in different than usual locations, the sides are left untouched. On the bottom is the microUSB port whereas the top is home to the power button in the center, with the headphone jack slightly to the left of it. It definitely gives the device a much more appealing look versus phones with the typical button layout.

The back of the phone is removable, however the battery is not. The removable cover has a slight brushed feel to it, so it has some grip, better than a lot of other devices on the market. The battery is safeguarded by the dual-SIM ports and the microSD card slot. I love when phone manufacturers put the slots underneath a cover, as it makes the overall look of the phone more streamlined. I am not a fan of SIM/microSD card slots that a tool is required to remove them.

Along with the slots being underneath the battery cover, the phone’s speaker is below the battery on the rear as well. The grill for the speaker goes well across the battery cover, but the speaker is on the left side of the device. It gets decently loud, but not as loud as the OnePlus One. It has good sound, but has little no low-end. At the end of the day it’s alright, especially when thinking it only costed $300.


The ZenFone 2 sports a 5.5 inch IPS LCD display with a FHD resolution. That means it is a 1080 x 1920 panel coming in at 401 ppi, definitely respectable. Overall, the display is cooler, which looks great when the brightness is maxed out.

Asus ZenFone 2 display

The display doesn’t wow me, but it doesn’t disappoint me. The color spectrum is good and picture is completely unsaturated. I personally like saturated displays, especially when looking at lots of colors. It has a slight faded look to images, but that is only noticeable when comparing it to other devices.

One thing I think they should have done better would be to increase the brightness range. There is little to any difference from using the device on low brightness versus full brightness. It is honestly the lowest brightness range I have seen a smart phone, so it something to note. Especially if you are outdoors a lot of the day.

For the most part in daylight I could see the display, but if it was a clear day and the sun was beating down, the display was hard to see. With low-light areas, the device doesn’t get very dim so you will definitely  be lighting up the room, no matter how dark.


This is the category that myself and probably most of the internet is concerned with. When a phone ships with 4 GB of RAM, you expect the device to perform very well and beat out much of the competition. One thing you should remember is that the device is running an Intel Atom processor that is made with a 22 nm process and has LPDDR3 RAM. It is clocked at 2.3 GHz, but it is a quad-core processor, not octa-core like much of the flagships of 2015.

On that note, the device could hold it’s against much of the flagship field. You can view our comparison to other flagships on this page. With my limited experience, I never saw a single stutter or had the device lag. Which is quite impressive. The ZenFone 2 is very good at using the 4 GB of RAM to its full potential, especially how Google caches apps in the background to quick load.

Asus ZenFone 2 AnTuTu

On some of my devices in the past, apps that were opened long ago, such as Google Chrome with a page open, would have to reload. On the ZenFone 2, that was never the case. It is definitely one of the best devices I’ve used when it comes to switching between apps.

One thing that is worth noting about performance, is that the ZenFone 2 is currently running the oldest version of Android Lollipop, 5.0. Many of the bugs are prevalent, so it would be interesting to see how it would handle on Android 5.1.1.

Another thing that surprised me was that Asus included a lot of pre-installed applications. When I saw a lot, I really mean a LOT, like more than Samsung. It is a waste of space, as I have not opened almost all of them, aside from Gallery, Camera, Themes, etc. It comes with apps such as Kids Mode, MiniMovie, Party Link, MyASUS, ZenCircle, ZenTalk, and more. One app that surprised me was Clean Master… really? Luckily, you can disable it.

One thing I don’t understand about phone manufacturers is why they think it’s a good idea to make an app that Google already has and is ten times better. I understand it benefits them by being able to track usage information, but there is NOT a single person I have met that likes bloatware. We may have a new king in the bloatware field, but the device’s performance is still up to snuff.

On top of the bloatware comes the Asus ZenUI, which isn’t the worst launcher, but it is nothing special. I didn’t find a use for it, so moved to Google Now Launcher. The ZenUI launcher just seemed a little clunky and didn’t perform as I’d like.

I have received three updates since I received the phone in May, but no major update just yet.


The Asus ZenFone 2 ships with a 13 megapixel rear-facing camera backed up with a 5 megapixel on the front of the device. On top of that, the Asus Camera app features a great library of different shooting modes from auto, low light, to even a time lapse mode.

Asus ZenFone 2 camera modes

The ZenFone 2’s rear-facing camera does not include OIS, but it does feature an f/2.0 aperture, so it captures a decent image. Like most smartphone cameras in today’s market, the camera is quite good in good lighting conditions. When thrust into any lower lit areas, be it outside or inside, the images get very grainy, but that is expected.

This is where the low light camera mode comes into play. When in low light conditions, the camera app will automatically suggest to go into Low Light mode. What this does is turn the 13 megapixel camera into a 3 megapixel camera. The end result is a brighter picture, but you obviously lose out on quality.

The camera will also recommend using the HDR mode just as it does with the low light mode. The HDR mode seemingly brightens up the picture, but it almost seems too bright. It does make the image look better by sharpening which upped the image size from 1.9 MB to 2.2 MB. Below are two images in the same lighting with the HDR mode and just the regular auto mode.

Overall the camera is a decent daily shooter. If you are a casual photography taking pictures of nature in the daylight or taking selfies, this camera will do just fine. The front-facing 5 megapixel camera with a wide angles lens can hold its own against top flagships, but the rear-facing camera is just behind. It really takes a hit in low light, but what smartphone camera doesn’t.


The Asus ZenFone 2 packs a 3,000 mAh battery and is powering a quad-core processor and FHD display, so battery life is above average. It has been a while since I used a device with a 1080p display, and I can tell you that I sure do miss the battery life.

During a normal day which just consists of an eight hour work day followed by 15-20 hours of up time, the device handled very well. I could go through an entire work day with say, two hours of screen on time and end around 60-70%. I use T-Mobile and connectivity isn’t an issue at my work, but with ZenFone 2 I only got 2-3 bars, so it drained on battery.

For the most part, it was quite relieving to have a device that could easily push into the five hour screen on time area, not that I do that often, but it is reassuring. It also helped that on standby, the battery didn’t drain very much. Without any interaction, the device could run through 3-5% per hour.


At the end of the day, you won’t find as good of bargain as the Asus ZenFone 2. Coming in at $300, the device claims a budget device title, but definitely performs like a flagship. The biggest selling point of the device, which is the amount of RAM, does not disappoint.

The design of the ZenFone 2 doesn’t stand out like other devices, but it feels well-put together and is comfortable to hold. Besides, the device isn’t purchased to be a looker, rather a performer. To me, the ergonomic design is just a plus to an already solid device. If you are in the market, head over to Amazon and just buy the ZenFone 2 already.

One last thing is that the ZenFone 2 is an international device, meaning it is unlocked, but that comes with a price. Reception is decent on GSM networks, but it isn’t as good as a device meant for the carrier.


About Author

I skateboard, listen to metal, write on my website FWNED, autocross, and love messing with new phones. Currently I'm using a Pixel XL running Pure Nexus with ElementalX as my daily driver.