Samsung Galaxy A51 vs Samsung Galaxy M21 vs Samsung Galaxy A42

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

Comparison mode:

Display

Size:

6.5 inches
6.4 inches
6.6 inches

Resolution:

2400 x 1080 pixels, 20:9 ratio, 405 PPI
2340 x 1080 pixels, 19.5:9 ratio, 403 PPI
1600 x 720 pixels, 20:9 ratio, 266 PPI

Technology:

Super AMOLED
Super AMOLED
Super AMOLED

Screen-to-body:

87.37 %
84.11 %
84.26 %

Peak brightness:

420 cd/m2 (nit)

Features:

60Hz refresh rate, Scratch-resistant glass (Corning Gorilla Glass 3), Ambient light sensor, Proximity sensor
Scratch-resistant glass (Corning Gorilla Glass 3), Proximity sensor
60Hz refresh rate, Ambient light sensor, Proximity sensor

Hardware

System chip:

Samsung Exynos 9611
Exynos 9611
Qualcomm Snapdragon 750G SM7225

Processor:

Octa-core, 2300 MHz, ARM Cortex-A73 and ARM Cortex-A53, 64-bit, 10 nm
Octa-core, 2300 MHz, Arm Cortex-A73 and Arm Cortex-A53, 64-bit, 10 nm
Octa-core, 2200 MHz, Kryo 570, 64-bit, 8 nm

GPU:

Mali-G72 MP3
Mali-G72 MP3
Adreno 619

RAM:

4GB LPDDR4
4GB LPDDR4
4GB LPDDR4

Internal storage:

128GB, available to use: 105.9 GB
64GB, available to use: 49 GB
128GB, available to use: 106 GB

Storage expansion:

microSDXC up to 512 GB
microSDXC up to 512 GB
microSDXC up to 1000 GB

Device type:

Smartphone
Smartphone
Smartphone

OS:

Android (11, 10), Samsung One UI
Android (11, 10), Samsung One UI
Android (11, 10), Samsung One UI

Battery

Capacity:

4000 mAh
6000 mAh
5000 mAh

Type:

Li - Polymer, Not user replaceable
Li - Polymer, Not user replaceable
Not user replaceable

Battery life test results:

Charging:

Fast charging
Fast charging
Samsung Adaptive Fast Charging

Max charge speed:

Wired: 15.0W

Camera

Rear:

Quad camera
Triple camera
Quad camera

Main camera:

48 MP (PDAF)
48 MP (PDAF)
48 MP (PDAF)

Specifications:

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

Second camera:

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

Specifications:

Aperture size: F2.2; Focal Length: 13 mm; Pixel size: 1.12 μm
Aperture size: F2.2; Focal Length: 12 mm; Sensor size: 1/4"; Pixel size: 1.12 μm
Aperture size: F2.2

Third camera:

5 MP (Macro)
5 MP (Depth information)
5 MP (Macro)

Specifications:

Aperture size: F2.4; Focal Length: 40 mm
Aperture size: F2.2
Aperture size: F2.4

Fourth camera:

5 MP (Depth information)
5 MP (Depth information)

Specifications:

Aperture size: F2.2; Sensor size: 1/5"; Pixel size: 1.12 μm
Aperture size: F2.4

Video recording:

3840x2160 (4K UHD) (30 fps), 1920x1080 (Full HD) (120 fps), 1280x720 (HD) (240 fps)
3840x2160 (4K UHD) (30 fps), 1920x1080 (Full HD), 1280x720 (HD) (240 fps)
3840x2160 (4K UHD) (30 fps), 1280x720 (HD) (480 fps)

Features:

Hyperlapse, EIS
EIS

Front:

32 MP (HDR)
20 MP (HDR)
20 MP (Autofocus)

Video capture:

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

Design

Dimensions:

6.24 x 2.90 x 0.31 inches (158.5 x 73.6 x 7.9 mm)
6.26 x 2.96 x 0.35 inches (159.0 x 75.1 x 8.9 mm)
6.47 x 2.99 x 0.34 inches (164.4 x 75.9 x 8.6 mm)

Weight:

6.07 oz (172.0 g)
6.63 oz (188.0 g)
6.81 oz (193.0 g)

Materials:

Back: Plastic; Frame: Plastic
Back: Plastic; Frame: Plastic

Biometrics:

2D Face unlock, In-screen fingerprint
2D Face unlock, Fingerprint (touch)
In-screen fingerprint

Keys:

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

Colors:

Prism Crush black, Prism Crush white, Prism Crush pink, Prism Crush blue
Midnight blue, Raven black
Prism Dot black, Prism Dot white, Prism Dot grey

Cellular

5G:

n1, n3, n5, n7, n8, n28, Sub-6

LTE (FDD):

Bands 1(2100), 2(1900), 3(1800), 4(AWS-1), 5(850), 7(2600), 8(900), 12(700 a), 13(700 c), 14(700 PS), 20(800 DD), 25(1900+), 26(850+), 28(700 APT), 29(700 d), 30(2300 WCS), 66(AWS-3), 71(600)
Bands 1(2100), 3(1800), 5(850), 7(2600), 8(900), 20(800 DD)
Bands 1(2100), 2(1900), 3(1800), 4(AWS-1), 5(850), 7(2600), 8(900), 12(700 a), 17(700 b), 20(800 DD), 28(700 APT)

LTE (TDD):

Bands 38(2600), 39(1900+), 41(2600+)
Bands 38(2600), 40(2300), 41(2600+)
Bands 38(2600), 40(2300), 41(2600+)

UMTS:

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

Data Speed:

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
LTE-A, HSDPA+ (4G) 42.2 Mbit/s, HSUPA 5.76 Mbit/s

Dual SIM:

Yes
Shared with microSD

SIM type:

Nano SIM
Nano SIM
Nano SIM

Multimedia

Headphones:

3.5mm jack
3.5mm jack
3.5mm jack

Speakers:

Earpiece, Loudspeaker
Earpiece, Loudspeaker
Earpiece, Loudspeaker

Features:

Dolby Atmos
Dolby Atmos

Screen mirroring:

Wireless screen share
Wireless screen share
Wireless screen share

Radio:

FM
FM

Additional microphone(s):

for Noise cancellation

Connectivity & Features

Bluetooth:

5.0
5.0
5.0

Wi-Fi:

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

USB:

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

Features:

Charging, OTG
Charging
Charging

Location:

GPS, A-GPS, Glonass, Galileo, BeiDou, Cell ID, Wi-Fi positioning
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, Hall (for flip covers)
Accelerometer, Gyroscope
Accelerometer, Gyroscope, Compass

Other:

NFC, ANT+
NFC

Regulatory Approval

FCC approval:

Date approved:

Nov 28, 2019
Apr 08, 2021

FCC ID value:

A3LSMA515FN
A3LSMA426U

Measured SAR:

Head:

0.89 W/kg
1.11 W/kg

Body:

1.18 W/kg
1.25 W/kg

Simultaneous Transmission:

1.56 W/kg
1.59 W/kg

Wireless Router:

1.12 W/kg
1.06 W/kg

Phablet:

2.76 W/kg
3.81 W/kg

Buyers information

Price:

$ 400
€ 340

User Manual:

This is the official Samsu​ng Galaxy A51 User Guide in English provided from the manufacturer.
This is the official Samsu​ng Galaxy A42 User Guide in English provided from the manufacturer.

In The Box:

This is the official Samsu​ng Galaxy M21 User Guide in English provided from the manufacturer.

Availability

Officially announced:

Dec 12, 2019
Mar 18, 2020
Sep 02, 2020
FCC OKs Cingular\'s purchase of AT&T Wireless