Xiaomi upgraded the 5.5" 1080p screen to one that promises 450nits of brightness and 72% coverage of NTSC colors. For the Note 3 it boasted "pixel-level dynamic contrast" yet the phone scored less than 1,000:1 contrast, will this new screen be better?
Yes - the Redmi Note 4 hits its target brightness, which is slightly higher than Note 3's. Thanks to improved black levels, however, contrast is now over 1,100:1.
There's an Increased contrast mode, but that only changes the dynamic contrast on a per-image basis. It still makes photos look punchier and doesn't affect color accuracy.
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|Black, cd/m2||White, cd/m2|
Automatic brightness is available, but it doesn't boost the screen - 440nits is the highest you get.
The high reflectivity of the screen prevents it from being very legible under bright sunlight. It scores a bit lower than even the Redmi Note 3, despite being slightly brighter.
The Note 4 uses an IPS LCD screen and it shows no color shifting at an angle.
The colors themselves are fairly accurate by default with an average deltaE of 5.3 and a maximum of 9.8. Those are numbers very similar to the LG V20 or a Sony Xperia XZ. The blues come on too strong, the white balance tends towards blue also.
We tried setting the white balance slider but found that the Standard screen mode is the most accurate. The average deltaE drops to a very good 2.8 and the maximum to 6.1. That's close the iPad Pro's numbers and better than a good deal of LCD-based flagships! This mode introduces a slight yellow tint, though, and shifts the white balance towards warm too. The maximum brightness drops to 415nits.
When you drag the brightness slider all the way down, the Redmi Note 4 screen drops to just 1 nit. This is great for using the phone late at night and you can enable the Reading mode to reduce the amount of blue light in the evening. This mode can be set to trigger automatically for select apps - say, Amazon Kindle or other apps that involve a lot of reading.
The Xiaomi Redmi Note 4 is a sometimes dual-SIM phone - it really depends on whether you need extra storage. Which you most likely do, with the 16GB model.
If you do have two SIMs, it's a toggle in the settings that flips which cards provides data over LTE. The phone supports all necessary 3G and 4G tech for the three major carriers in China. VoLTE is supported, soon it will replace 2G voice in busy city centers as it supports many more calls per cell.
Locally, you get fast Wi-Fi a/b/g/n/ac on 2.4GHz and 5GHz (802.11ac was missing from the Redmi Pro). Wi-Fi screen sharing is available too, also Bluetooth 4.2 but no NFC.
The IR blaster gives the Redmi Note 4 control over your equipment at home - including things like cameras (some DSLRs have IR remotes), fans (Xiaomi makes a smart fan, believe it or not) and others.
The Xiaomi Redmi Note 4 has a 4,100mAh battery - about the same as the Note 3 or Redmi Note 3 (withing 50-100mAh). It uses the same Helio X20 chipset that the Redmi Pro uses, but an IPS LCD screen instead of an AMOLED.
The X20 chipset is built on a 20nm process, meaning it should be more efficient than the 28nm chips (Snapdragon 650/652, Helio P10/X10). Even so, the Redmi Note 4 lasted less than the Note 3 (S650) we tested, scoring an 83 hour Endurance rating (down from 93 hour). That's as long as the Redmi Pro managed (80h). If you need two SIMs, then the Note 4 Endurance drops to 70 hours.
Individual tests are quite similar to the other two Redmis. The talk time is as long as you would ever need (even if not impressive for a 4,100mAh battery), the web browsing time is some of the best, the video playback good-not-great.
Our endurance rating denotes how long a single battery charge will last you if you use the Redmi Note 4 for an hour each of telephony, web browsing, and video playback daily. We've established such usage pattern so our battery results are comparable across devices in the most common day-to-day tasks. 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.