Xiaomi Redmi Note 4 (S625) review: Take Note!

Display

Xiaomi Redmi Note 4 has a 5.5" IPS LCD screen of 1080p resolution (401ppi) with no color shifting at an angle. The company promises 1000:1 contrast ratio and 72% coverage of NTSC color spectrum.

The Snapdragon-powered unit of Redmi Note 4 exceeds the display scores of both Redmi Note 3 and Redmi Note 4 with Helio X20. It has improved black levels and higher maximum brightness of 484 nits. These new tweaks have led to an excellent contrast ratio of 1503:1.

There's an Increased contrast mode, but that only changes the dynamic contrast on a per-image basis. It makes the photos look punchier and doesn't affect color accuracy.

Automatic brightness is available, but it doesn't boost the screen - 484nits is the highest you get.

When you drag the brightness slider all the way down, the Redmi Note 4 screen drops to just 2 nits. This is great for using the phone comfortably in the dark, 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 screen time.

Sunlight legibility is okay on the Redmi Note 4 Snapdragon Edition, and surprisingly much better than the Helio X20 model. It suffers from washed-out colors in the sun, but other than that you will be able to see what's happening on the screen quite well.

Sunlight contrast ratio

The colors themselves are fairly accurate by default with an average deltaE of 5.2 and a maximum of 9.8. The whites and grays have a bluish tint, but other than that, the default Auto mode offers a good color presentation.

We tried setting the white balance slider and found that the Standard screen mode is the most accurate. The average deltaE drops to a very good 3.6 and the maximum to 6.8. This mode introduces a slight yellow tint, though, and shifts the white point towards warmer tones.

Battery life

The Xiaomi Redmi Note 4 has a 4,100mAh battery, the same as the Helio model, but the energy efficient Snapdragon 625 should help it achieve a better battery endurance. The Note 4 supports regular 5V/2A charging, which restores 25% of the battery in 30 minutes of charging, 95% in 2 hours, and 100% in 3h.

Indeed, the Snapdragon 625 chip lived up to our expectations. Combined with the large battery, the Redmi Note 4 easily scored one of the best results in our battery test with a 119-hour Endurance rating. It did a fabulous job in all tested scenarios - video, calls, web browsing and even stand-by performance.

The rating of 119 hours means you can rely on the Redmi Note 4 to last that long if you do an hour of 3G calls, web browsing, and video playback each day.

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 this 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.

Connectivity

The Xiaomi Redmi Note 4 can be a dual-SIM phone if you'd like it to be - it really depends on whether you need extra storage.

If you do have two SIMs, a toggle in the settings selects which card will provide data over LTE. 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. Wi-Fi screen sharing is available too, also Bluetooth 4.1, 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.

Finally, the Redmi Note 4 comes with FM radio, but it lacks RDS support.