Xiaomi Redmi 9

Samsung Galaxy A21s 4GB/64GB

os

Android 10, MIUI 12

Android 10, One UI 2.0

RAM

4 GB

4 GB

ROM

64 GB

64 GB

expandable

microSDXC (dedicated slot) GB

512 GB

CPU

Octa-core (2x2.0 GHz Cortex-A75 & 6x1.8 GHz Cortex-A55)

Octa-core (4x2.0 GHz Cortex-A55 & 4x2.0 GHz Cortex-A55)

GPU

Mali-G52 MC2

Mali-G52

SoC

Mediatek Helio G80 (12 nm)

Exynos 850 (8nm)

number of cores

8core

8core

features

LED flash, panorama, HDR

featurues

HDR

primary

Quad:
13 MP, f/2.2, 28mm (wide), 1/3.1", 1.12m, PDAF
8 MP, f/2.2, 118 (ultrawide), 1/4.0", 1.12m
5 MP, f/2.4, (macro)
2 MP, f/2.4, (depth)

Quad:
48 MP, f/2.0, 26mm (wide), 1/2.0", 0.8m, PDAF
8 MP, f/2.2, 123 (ultrawide), 1/4.0", 1.12m
2 MP, f/2.4, (macro)
2 MP, f/2.4, (depth)

secondary

8 MP, f/2.0, 27mm (wide)

13 MP, f/2.2, (wide), 1/3.1", 1.12m

video

1080p@30fps

1080p@30fps

capacity

5020mAh

5000mAh

charging

Fast charging 18W

Fast charging 15W

type

Li-Polymer (non-removable)

Li-Polymer (non-removable)

build

Glass front (Gorilla Glass 3), plastic back, plastic frame

color

Carbon Gray, Ocean Green, Blue

dimension

163.3 x 77 x 9.1 mm

163.7 x 75.3 x 8.9 mm

display

IPS LCD capacitive touchscreen, 16M colors

PLS TFT capacitive touchscreen, 16M colors

resolution

1080 x 2340 pixels, 19.5:9 ratio (~395 ppi density)

screen

6.53"

6.5"

weight

198 gm

192 gm

GPS

Yes, with A-GPS, GLONASS, GALILEO, BDS

NFC

Yes (market/region dependent)

USB

2.0, Type-C 1.0 reversible connector, USB On-The-Go

2.0, Type-C 1.0 reversible connector

bluetooth

5.0, A2DP, LE

5.0, A2DP, LE

internet

GSM / HSPA / LTE

2G/3G/4G/LTE

wifi

Wi-Fi 802.11 b/g/n, Wi-Fi Direct, hotspot

Wi-Fi 802.11 a/b/g/n/ac, dual-band, Wi-Fi Direct, hotspot

radio

Wireless FM radio (no wired headphones required)

FM Radio

sensors

Fingerprint (rear-mounted), accelerometer, proximity, compass

Fingerprint (rear-mounted), accelerometer, gyro, proximity, compass