The Asus Zenfone Max has a 5.5-inch 720p display. If you're at all familiar with Asus's naming convention, you could have extracted that info from the model name ZC550KL - the 55 in 550 means 5.5 inches, while the zero stands for HD resolution. FullHD resolution would have been 551, but there aren't Max versions with such, only Zenfone 2's and the Zenfone Selfie.
Anyway, the numbers make up for a pixel density of 267ppi, and you can tell pixels are larger than recent trends by looking at our microscope shot. It also reveals a standard RGB pixel arrangement with equal numbers of the three base color subpixels.
The screen is covered in Gorilla Glass 4 for scratch and shatter resistance.
In terms of maximum brightness, the smartphone does a great job. Its output is dependent on which one of the Battery saver modes is selected, and the maximum available brightness setting is higher in Performance mode, than say, in Normal.
That said, the Auto toggle will produce an equal result in bright sunlight regardless of power mode, also brighter than what you could achieve manually. It can go even brighter than the Moto X Play, which was already an excellent performer.
The screen's contrast remains unaffected by screen modes, and at a very good level around 1100:1. While that's no match for the Moto X Play, which can go as high 1520:1 thanks to its deep blacks, the Max's display outperforms most of the competition in this respect.
|Display test||100% brightness|
|Black, cd/m2||White, cd/m2|
Color reproduction is one area Asus gives you plenty of control. Tinkering with the sliders in the Splendid app lets you adjust color temperature, hue and saturation and also gives you the option to filter out the blue tones light, if you consider it to be an issue in the hours prior to bedtime.
Alternatively, you can leave it in the default Balanced mode, where you get a pretty good color reproduction with an average deltaE of 4.2, not properly calibrated, but also more accurate than the flagship LG G5's 5.6, for instance. Even the maximum deviation is 6.8, which is quite constrained given that we often see numbers above 10.
The standard DeltaE 2000 deviation is used to describe the accuracy of the screen's color rendering. We test the screen with a set of over 100 different color and grayscale patterns to determine the accuracy of the color reproduction.
Even when a phone's screen color reproduction is off, you would still have a hard time noticing a color cast without a reference as the human eye is quite quick to adjust and normalize colors.
Also, the display colors are a matter of personal taste and perception so consider this test data only if you are concerned about presenting color-critical content on the mobile screen.
Any deviation in DeltaE 2000 of above 10 is considered a visible error in color reproduction on the display. A DeltaE 2000 deviation between 4 and 10 is considered okay or acceptable color performance. A DeltaE 2000 deviation below 4 is considered good, but professional color calibration requires a deviation between 1 and 2.
Things aren't so great in bright outdoor light, where the Zenfone Max struggles, despite the high maximum brightness - quite possibly due to the reflective screen. Even so, it's markedly better than the Zenfone Selfie and on par with the Zenfone 2 ZE551ML.
The Zenfone Max is a Dual SIM device with the full range of 2G/3G/4G bands supported on both cards. LTE is Cat.4 with theoretical speeds of up to 150Mbps down and 50Mbps up.
There is Wi-Fi 802.11 b/g/n, single-band, no Wi-Fi ac but, on a positive note, there's Wi-Fi Direct and hotspot support.
Bluetooth is in its 4.0 version, there's a GPS receiver with added GLONASS and Beidou support.
An FM radio receiver is provided too, but the Max lacks NFC.
The microUSB port comes with USB host support for attaching your choice of peripherals. You can also use the Max to charge other devices with the bundled USB OTG adapter. There's a standard 3.5mm jack too.
There's also a dedicated microSD card slot for storage expansion, which takes cards of up to 64GB.
The Zenfone Max's claim to fame is the battery, a 5,000mAh lithium polymer unit, sealed inside. It's one of the largest cells available in a phablet from a major brand, with most offerings hovering around the 4,000mAh mark. Coupled with the modest Snapdragon 410 chipset, it's a recipe for excellent endurance.
Indeed, that's what the Zenfone Max delivers. Some 20+ hours of web browsing, close to 16 hours of video playback and almost 28 hours of voice calls are all great numbers. That adds up to an endurance rating of 121 hours in our proprietary test - meaning second spot in our all-time chart. The leader is the Gionee Marathon M5, which has a 6,020 milliamp-hour battery and pretty similar specs.
The battery testing procedure is described in detail in case you're interested in the nitty-gritties. You can also check out our complete battery test table, where you can see how all of the smartphones we've tested will compare under your own typical use.