Samsung Galaxy S4 vs Samsung Galaxy A21s vs Xiaomi Redmi Note 9

Compare phone and tablet specifications of up to three devices at once.

Display

Size:

5.0 inches
6.5 inches
6.5 inches

Resolution:

1920 x 1080 pixels, 441 PPI
1600 x 720 pixels, 20:9 ratio, 270 PPI
2340 x 1080 pixels, 19.5:9 ratio, 395 PPI

Technology:

Super AMOLED
TFT
IPS LCD

Screen-to-body:

71.91 %
82.94 %
83.52 %

Colors:

16 777 216

Touchscreen:

Capacitive, Multi-touch

Features:

Scratch-resistant glass (Corning Gorilla Glass 3), Ambient light sensor, Proximity sensor
Proximity sensor
Scratch-resistant glass (Corning Gorilla Glass 5), Ambient light sensor, Proximity sensor

Hardware

System chip:

Qualcomm Snapdragon 600 8974
Samsung Exynos 850
MediaTek Helio G85

Processor:

Quad-core, 1900 MHz, Krait 300
Octa-core, 2000 MHz, Arm Cortex-A55, 64-bit
Octa-core, 2000 MHz, Arm Cortex-A75 and ArmCortex-A55, 64-bit, 12 nm

GPU:

Adreno 320
Mali-G76
Mali G52 MC2

RAM:

2GB LPDDR3
3GB LPDDR4
3GB LPDDR4

Internal storage:

64GB
32GB (eMMC 5.1), available to use: 19.5 GB
64GB (eMMC 5.1)

Storage expansion:

microSDXC up to 64 GB
microSDXC up to 512 GB
microSDXC up to 128 GB

Device type:

Smartphone
Smartphone
Smartphone

OS:

Android (5.0 Lollipop, 4.4.2, 4.3, 4.2.2)
Android (10), Samsung One UI
Android (10), Xiaomi MI UI

Battery

Capacity:

2600 mAh
5000 mAh
5020 mAh

Type:

Li - Ion, User replaceable
Li - Polymer, Not user replaceable
Li - Polymer, Not user replaceable

Battery life test results:

Charging:

Fast charging
Fast charging, Reverse charging

Max charge speed:

Wired: 18.0W

Camera

Rear:

Single camera
Quad camera
Quad camera

Main camera:

13 MP (Autofocus, CMOS image sensor, BSI sensor)
48 MP (PDAF)
48 MP (PDAF)

Specifications:

Aperture size: F2.2; Focal length: 31 mm; Sensor size: 1/3.06"; Pixel size: 1.14 μm
Aperture size: F2.0; Focal length: 26 mm; Sensor size: 1/2"; Pixel size: 0.8 μm
Aperture size: F1.8; Sensor size: 1/2"; Pixel size: 0.8 μm

Second camera:

8 MP (Ultra-wide)
8 MP (Ultra-wide)

Specifications:

Aperture size: F2.2; Sensor size: 1/4"; Pixel size: 1.12 μm
Aperture size: F2.2; Sensor size: 1/4"; Pixel size: 1.2 μm

Third camera:

2 MP (Macro)
2 MP (Macro, Autofocus)

Specifications:

Aperture size: F2.4
Aperture size: F2.4; Pixel size: 1.75 μm

Fourth camera:

2 MP (Depth information)
2 MP

Specifications:

Aperture size: F2.4
Aperture size: F2.4; Sensor size: 1/5"; Pixel size: 1.7 μm

Video recording:

1920x1080 (Full HD) (30 fps)
1920x1080 (Full HD) (30 fps)
1920x1080 (Full HD) (30 fps), 1280x720 (HD) (120 fps)

Features:

EIS

Front:

2 MP
13 MP
13 MP (HDR)

Video capture:

1920x1080 (Full HD)
1920x1080 (Full HD)
1920x1080 (Full HD)

Design

Dimensions:

5.38 x 2.75 x 0.31 inches (136.6 x 69.8 x 7.9 mm)
6.44 x 2.96 x 0.35 inches (163.7 x 75.3 x 8.9 mm)
6.39 x 3.04 x 0.35 inches (162.3 x 77.2 x 8.9 mm)

Weight:

4.59 oz (130.0 g)
6.77 oz (192.0 g)
7.02 oz (199.0 g)

Materials:

Back: Plastic
Frame: Plastic

Resistance:

Splash

Biometrics:

2D Face unlock, Fingerprint (touch)
Fingerprint (touch)

Features:

Notification light

Keys:

Left: Volume control; Right: Lock/Unlock key
Right: Volume control, Lock/Unlock key
Right: Volume control, Lock/Unlock key

Colors:

Black, Blue, Red, White
Black, White, Blue, Red
Forest green, Polar white, Midnight gray

Cellular

LTE (FDD):

Bands 1(2100), 3(1800), 5(850), 7(2600), 8(900), 18(800 Lower)
Bands 1(2100), 2(1900), 3(1800), 5(850), 7(2600), 8(900), 20(800 DD), 28(700 APT)
Bands 1(2100), 2(1900), 3(1800), 4(AWS-1), 5(850), 7(2600), 8(900), 20(800 DD), 28(700 APT)

LTE (TDD):

Bands 38(2600), 40(2300), 41(2600+)
Bands 38(2600), 40(2300), 41(2600+)

UMTS:

Bands 5(850), 8(900), 2(1900), 1(2100)
Bands 5(850), 8(900), 2(1900), 1(2100)
Bands 5(850), 8(900), 4(1700/2100), 2(1900), 1(2100)

Data Speed:

LTE Cat 3 (100/50 Mbit/s), HSDPA+ (4G) 42.2 Mbit/s, HSUPA 5.76 Mbit/s, UMTS
LTE-A, HSDPA+ (4G) 42.2 Mbit/s, HSUPA 5.76 Mbit/s
LTE-A, HSDPA+ (4G) 42.2 Mbit/s, HSUPA 5.76 Mbit/s

Dual SIM:

Yes
Yes

SIM type:

Micro SIM
Nano SIM
Nano SIM

VoLTE:

Yes
Yes

Multimedia

Headphones:

3.5mm jack
3.5mm jack
3.5mm jack

Speakers:

Earpiece, Loudspeaker
Earpiece, Loudspeaker
Earpiece, Loudspeaker

Features:

Album art cover, Background playback

Screen mirroring:

DLNA, Wireless screen share, MHL
Wireless screen share
Wireless screen share

Additional microphone(s):

for Noise cancellation

Connectivity & Features

Bluetooth:

4.0
5.0
5.0

Wi-Fi:

802.11 a, b, g, n, ac, dual-band; Hotspot, Wi-Fi Direct
802.11 a, b, g, n, ac, dual-band; Wi-Fi Direct, Hotspot
802.11 a, b, g, n, ac, dual-band; Wi-Fi Direct, Hotspot

USB:

microUSB, USB 2.0
Type-C (reversible), USB 2.0
Type-C (reversible), USB 2.0

Features:

Mass storage device, OTG, Charging, Video out
Charging
Charging

HDMI:

Yes

Location:

GPS, A-GPS, Glonass
GPS, A-GPS, Glonass, Galileo, BeiDou, Cell ID, Wi-Fi positioning
GPS, A-GPS, Glonass, Galileo, BeiDou, Cell ID, Wi-Fi positioning

Sensors:

Accelerometer, Gyroscope, Compass, Thermometer, Gesture, Humidity, Barometer
Accelerometer, Gyroscope
Accelerometer, Gyroscope, Compass

Other:

NFC, ANT+, Infrared, Tethering, Computer sync, OTA sync
NFC
NFC, Infrared

Phone features

Notifications:

Haptic feedback, (MP3)

Other features:

Voice dialing, Voice commands, Voice recording

Regulatory Approval

FCC approval:

Date approved:

Mar 14, 2013

FCC ID value:

A3LGTI9505 link

Measured SAR:

Head:

0.50 W/kg

Body:

0.65 W/kg

Simultaneous Transmission:

1.17 W/kg

Wireless Router:

0.67 W/kg

Buyers information

Price:

€ 240

User Manual:

This is the official Samsu​ng Galaxy A21s User Guide in English provided from the manufacturer.

In The Box:

22.5W Charger, Simple protective cover, USB Type-C cable, SIM eject tool, User guide, Warranty card

Availability

Officially announced:

Mar 14, 2013
May 15, 2020
Apr 30, 2020
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