Xiaomi Redmi S2 (Y2) review

Display

Xiaomi is among the first makers to introduce the tall display on a budget smartphone. The 18:9 display is 5.99" big on the Redmi S2, which is a bit of a stretch for its 720x1440 resolution. Still, at 269ppi density we saw no pixelization, and while the screen won't top any charts, it is quite enough for the class.

The Redmi S2 display has a maximum brightness of 500 nits, but its black levels aren't that deep, which led to an average contrast ratio of 1000:1. But that's the contrast Xiaomi is promising, and apparently, it has delivered.

Sunlight legibility is nothing to phone home about, although its score is still respectable especially for a budget phone. In real-world terms, the handset remains perfectly usable outdoors. Just don't angle the sun straight at it.

Sunlight contrast ratio

• Apple iPhone X
  5.013
• OnePlus 5T
  4.789
• Samsung Galaxy S8
  4.768
• Samsung Galaxy S8+
  4.658
• Samsung Galaxy S9
  4.63
• Samsung Galaxy S6 edge+
  4.615
• Samsung Galaxy S9+
  4.537
• Motorola Moto Z2 Play
  4.459
• Oppo R11
  4.454
• Samsung Galaxy S7 edge
  4.439
• OnePlus 3
  4.424
• Samsung Galaxy S7
  4.376
• HTC One A9
  4.274
• Oppo R15 Pro
  4.251
• Samsung Galaxy Note7
  4.247
• Samsung Galaxy A3
  4.241
• Nokia 8
  4.239
• Google Pixel 2 XL (pre-update)
  4.234
• OnePlus 3T
  4.232
• Google Pixel XL
  4.164
• ZTE Axon 7
  4.154
• Samsung Galaxy Note8
  4.148
• Meizu Pro 7 Plus
  4.147
• Samsung Galaxy S6 edge
  4.124
• Samsung Galaxy A7 (2017)
  4.124
• Huawei Mate 10 Pro (normal)
  4.096
• Samsung Galaxy Note5
  4.09
• Huawei P20 Pro
  4.087
• Nokia 6 (2018)
  4.052
• Google Pixel 2 (pre-update)
  4.023
• LG V30
  4.022
• Huawei Nexus 6P
  4.019
• Samsung Galaxy J7 Pro
  3.998
• OnePlus X
  3.983
• Vivo Xplay5 Elite
  3.983
• Apple iPhone 7
  3.964
• Oppo R7s
  3.964
• Apple iPhone 8 (True Tone)
  3.957
• Huawei P9 Plus
  3.956
• Meizu Pro 6 Plus
  3.935
• Lenovo Moto Z
  3.931
• Samsung Galaxy A7 (2016)
  3.918
• OnePlus 5
  3.914
• Samsung Galaxy C5
  3.911
• Samsung Galaxy C7
  3.896
• Samsung Galaxy A5
  3.895
• Samsung Galaxy J7 outdoor
  3.879
• Samsung Galaxy J2 outdoor
  3.873
• Motorola Moto G6 Plus
  3.865
• Samsung Galaxy A8
  3.859
• Samsung Galaxy A8 (2018)
  3.842
• Sony Xperia XZs
  3.818
• Samsung Galaxy A9 (2016)
  3.817
• Motorola Moto X (2014)
  3.816
• Samsung Galaxy J7 (2017)
  3.812
• Samsung Galaxy A5 (2017)
  3.804
• Samsung Galaxy J7 (2016) outdoor mode
  3.802
• Xiaomi Redmi Pro
  3.798
• LG V20 Max auto
  3.798
• Sony Xperia XZ
  3.795
• Samsung Galaxy A5 (2016)
  3.789
• Apple iPhone 6s
  3.783
• Meizu Pro 5
  3.781
• Microsoft Lumia 650
  3.772
• Xiaomi Mi 6
  3.767
• Sony Xperia XZ1
  3.765
• Samsung Galaxy J7 (2016)
  3.756
• Nokia 8 Sirocco
  3.745
• Sony Xperia XZ1 Compact
  3.729
• Apple iPhone 8 Plus (True Tone)
  3.725
• Oppo F1 Plus
  3.709
• Vivo X5Pro
  3.706
• Samsung Galaxy A3 (2017)
  3.688
• Huawei P20
  3.683
• Apple iPhone SE
  3.681
• Huawei Mate 9
  3.68
• Samsung Galaxy A7
  3.679
• Sony Xperia XZ2 Compact
  3.675
• Meizu PRO 6
  3.659
• BlackBerry Priv
  3.645
• Sony Xperia XA1 Ultra
  3.597
• Apple iPhone 7 Plus
  3.588
• Sony Xperia XZ2
  3.58
• LG G6
  3.556
• Apple iPhone 6s Plus
  3.53
• Motorola Moto Z Play
  3.526
• Samsung Galaxy J3 (2016)
  3.523
• Samsung Galaxy J3 (2016) outdoor mode
  3.523
• Acer Jade Primo
  3.521
• Microsoft Lumia 950
  3.512
• Oppo R7 Plus
  3.499
• Nokia 7 plus
  3.479
• nubia Z11
  3.466
• Huawei P10 Plus
  3.456
• HTC U Ultra
  3.453
• Motorola Moto G6
  3.448
• Sony Xperia XA2 Ultra
  3.445
• Samsung Galaxy J7
  3.422
• Motorola Moto G6 Play
  3.419
• Meizu MX5
  3.416
• LG V20
  3.402
• Samsung Galaxy A6 (2018)
  3.397
• Xiaomi Redmi Note 5 AI Dual Camera
  3.393
• Huawei P10
  3.379
• Samsung Galaxy J5 (2016)
  3.378
• Oppo R9s
  3.352
• Honor 8 Pro
  3.341
• Oppo F7
  3.333
• Oppo R7
  3.32
• Lenovo P2
  3.316
• Archos Diamond Omega
  3.305
• Honor 9
  3.289
• Xiaomi Mi 5s
  3.276
• Nokia 5
  3.261
• Nokia 6 (Chinese version)
  3.244
• Nokia 6 (Global version)
  3.238
• Samsung Galaxy J2
  3.235
• Sony Xperia X Performance
  3.234
• Xiaomi Mi Note 2
  3.228
• Motorola Moto X Play
  3.222
• Oppo F3 Plus
  3.218
• Huawei Mate 9 Pro
  3.206
• Huawei P9
  3.195
• Xiaomi Mi Mix 2
  3.19
• ZTE Nubia Z17
  3.159
• Oppo R11s
  3.153
• Lenovo Vibe Shot
  3.113
• HTC U11 Life
  3.108
• Motorola Moto X Force
  3.105
• LG Nexus 5X
  3.092
• HTC U11
  3.089
• Xiaomi Redmi S2 (Y2)
  3.077
• Huawei Mate S
  3.073
• Microsoft Lumia 640 XL
  3.065
• Apple iPhone 6 Plus
  3.023
• Asus Zenfone 4 ZE554KL
  3.019
• Sony Xperia XA1
  3.012
• Motorola Moto X4
  3.012
• Sony Xperia L1
  2.994
• Sony Xperia X
  2.989
• LG Q6
  2.987
• Huawei P10 Lite
  2.974
• Samsung Galaxy Note
  2.97
• Huawei P20 Lite
  2.952
• Xiaomi Redmi 5
  2.951
• Huawei Mate 8
  2.949
• Sony Xperia XA2
  2.938
• Oppo Realme 1
  2.932
• Xiaomi Redmi 4
  2.92
• Xiaomi Redmi 3S
  2.913
• Xiaomi Redmi 5 Plus
  2.913
• Sony Xperia XA Ultra
  2.906
• LG G5
  2.905
• Huawei Honor View 10
  2.896
• Xiaomi Redmi 3s Prime
  2.893
• Xiaomi Mi 5s Plus
  2.884
• Sony Xperia XZ Premium (sRGB)
  2.877
• Sony Xperia XZ Premium
  2.877
• Sony Xperia Z5
  2.876
• Nokia 3
  2.871
• Microsoft Lumia 550
  2.851
• Lenovo Moto M
  2.813
• Xiaomi Redmi 3 Pro
  2.803
• Sony Xperia Z5 compact
  2.784
• Honor 10 (Vivid)
  2.757
• Nokia 2
  2.752
• Meizu MX6
  2.751
• LG V10
  2.744
• Huawei Mate 10 (normal)
  2.742
• Motorola Moto G5S Plus
  2.737
• Xiaomi Redmi 3
  2.735
• Huawei Honor 7X
  2.734
• Xiaomi Redmi Note 4 (S625)
  2.714
• Meizu M5
  2.71
• Sony Xperia M5
  2.69
• Xiaomi Mi A1
  2.689
• Huawei P9 Lite
  2.679
• Xiaomi Redmi 4 Prime
  2.679
• vivo V7+
  2.671
• Vivo V3Max
  2.659
• Xiaomi Mi Mix
  2.658
• Huawei Mate 10 Lite
  2.654
• Oppo F5
  2.653
• Doogee Mix
  2.642
• Xiaomi Mi 4i
  2.641
• Xiaomi Redmi 4a
  2.635
• Xiaomi Mi 5X (Standard)
  2.616
• Sony Xperia XA
  2.609
• Motorola Moto G4 Plus (max auto)
  2.582
• Motorola Moto G4 Plus
  2.582
• Meizu M5s
  2.58
• Xiaomi Mi 4c
  2.574
• LeEco Le Max 2
  2.567
• Asus Zenfone 3 ZE552KL
  2.563
• Huawei P Smart
  2.563
• Microsoft Lumia 640
  2.563
• Xiaomi Mi Max 2
  2.561
• Xiaomi Redmi Note 5A (Y1)
  2.556
• HTC U11+
  2.556
• Lenovo K6 Note
  2.544
• Lenovo Moto G4
  2.544
• Oppo F1
  2.528
• Sony Xperia Z5 Premium
  2.525
• Huawei Honor 7 Lite / Honor 5c
  2.506
• Sony Xperia M4 Aqua
  2.503
• BlackBerry Motion
  2.494
• Oppo F1s
  2.481
• Motorola Moto G
  2.477
• Lenovo Vibe K5 Plus
  2.473
• Huawei G8
  2.471
• Huawei nova
  2.467
• Sony Xperia Z
  2.462
• Lenovo Vibe K5
  2.459
• Meizu m3 max
  2.447
• Xiaomi Mi 4
  2.424
• Xiaomi Mi 5X (Auto)
  2.417
• HTC 10 evo
  2.407
• Huawei Honor 7
  2.406
• Vivo V7
  2.404
• Sony Xperia E5
  2.386
• ZUK Z1 by Lenovo
  2.382
• HTC 10
  2.378
• Oppo F3
  2.376
• vivo V5 Plus
  2.371
• Meizu m1 note
  2.362
• Huawei nova plus
  2.329
• Razer Phone
  2.328
• HTC One E9+
  2.305
• Alcatel One Touch Hero
  2.272
• Sony Xperia L2
  2.266
• Lenovo Vibe K4 Note
  2.254
• HTC U11+ (EU)
  2.253
• Sony Xperia C5 Ultra
  2.253
• Xiaomi Redmi Note 3 (MediaTek)
  2.249
• Sony Xperia C4 Dual
  2.235
• Xiaomi Mi Note
  2.234
• Motorola Moto G (2014)
  2.233
• LG Nexus 5
  2.228
• Huawei P8
  2.196
• Meizu M5 Note
  2.189
• Huawei Honor 6
  2.169
• Xiaomi Redmi Note 2
  2.166
• OnePlus Two
  2.165
• HTC One X
  2.158
• LG Aka
  2.145
• Xiaomi Redmi Note 4 (X20)
  2.145
• Archos 50 Diamond
  2.134
• Xiaomi Redmi Note
  2.119
• Xiaomi Mi 4S
  2.095
• Acer Liquid X2
  2.084
• Huawei P8lite
  2.078
• vivo V5
  2.059
• Moto G 3rd gen max manual
  2.026
• Xiaomi Mi 3
  2.001
• Xiaomi Mi Max
  1.996
• Sony Xperia E4g
  1.972
• OnePlus One
  1.961
• Sony Xperia Z2
  1.944
• Meizu m3 note
  1.923
• BlackBerry Leap
  1.892
• Meizu m2 note
  1.892
• HTC Butterfly
  1.873
• Sony Xperia Z1 Compact
  1.772
• ZTE Nubia Z9 mini
  1.759
• Sony Xperia U
  1.758
• Asus Zenfone Selfie
  1.68
• Motorola Moto E (2nd Gen)
  1.675
• ZTE Nubia Z9
  1.659
• Jolla Jolla
  1.605
• Motorola Moto E
  1.545
• Sony Xperia M
  1.473
• Sony Xperia L
  1.351
• Xiaomi Redmi 2
  1.311
• HTC Desire C
  1.3
• Nokia X
  1.291
• Meizu MX
  1.221
• Sony Xperia E
  1.215

The default (Standard with Auto setting) color rendering is average - the screen offers mostly accurate colors, but it looks a bit bluish, and the representation of the white color is way colder than it should be (DeltaE of 14). The overall color rendering out of the box worked out to an average DeltaE of 7.6, which is fine if you are okay with the cooler looking whites.

You can switch from Auto contrast to Standard and get rid of the blue tint. This mode will give you much more accurate color presentation with an average deltaE of 3.6 and a maximum deviation of 7 at point white.

Battery life

The Redmi S2 is powered by a 3,080mAh sealed battery - the same as on the Y1. It supports regular 5V/2A charging, which restores about 30% of the battery in 30 minutes of charging from zero. Not exactly fast, but expected for the price segment.

The S2 has the same energy-efficient Snapdragon 625 chip as many other Redmi phones, so we expected the S2 (or Y2) to do better than the Y1 (S435) in spite of the larger screen.

And it did - the Redmi S2 easily scored an excellent result in our battery test with a 92-hour Endurance rating. It did a great job in all tested scenarios - video playback, calls, web browsing and stand-by performance. That's a significant improvement over the Y1 with its 74h rating.

Our endurance rating denotes how long a single battery charge will last you if you use the Redmi S2 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.

Loudspeaker

The Redmi S2 has a single bottom-firing speaker at its disposal. It scored a Very Good mark in our loudness test, but its output is not that rich to impress. Still, we've seen plenty of worse, so we are fine with what we got for this class.

Audio quality

The Xiaomi Redmi S2 pulled off a beautiful performance in our audio output quality test. It was very loud both with an active external amplifier and with our standard headphones set and its accuracy was basically flawless.

In fact, we could barely register any change when the headphones were plugged in, which is a real rarity among smartphones. And when you consider that it's not even a flagship, but a mere mid-ranger, this is a properly impressive performance.

Xiaomi Redmi S2 frequency response

You can learn more about the tested parameters and the whole testing process here.