Samsung Galaxy S21 Ultra vs Galaxy A51

76 out of 100

52 out of 100

Here we compared two smartphones: the 6.8-inch Samsung Galaxy S21 Ultra (with Exynos 2100) that was released on January 14, 2021, against the Samsung Galaxy A51, which is powered by Exynos 9 Octa 9611 and came out 13 months before. On this page, you will find tests, full specs, strengths, and weaknesses of each of the devices.

Differences
Review
Specs
Benchmarks
Battery life
Camera
Comments

Key differences

An overview of the main advantages of each smartphone

Reasons to consider the Samsung Galaxy S21 Ultra

Waterproof body (IP68 classification)
The rear camera has a 10x optical zoom
3.4x better performance in AnTuTu Benchmark (833K versus 246K)
Higher display refresh rate – 120 Hz
Comes with 1000 mAh larger battery capacity: 5000 vs 4000 mAh
Shows 18% longer battery life (31:14 vs 26:33 hours)
Delivers 60% higher peak brightness (1023 against 638 nits)
27% higher pixel density (515 vs 405 PPI)
Handles wireless charging up to 15W
Newer Bluetooth version (v5.2)
Optical image stabilization
Has a 0.3 inch larger screen size
More energy-efficient CPU – Exynos 2100

Reasons to consider the Samsung Galaxy A51

Expandable storage via MicroSD card up to 512GB
Weighs 55 grams less
Includes a 3.5 mm headphone audio jack port

Review

Evaluation of Samsung Galaxy S21 Ultra and Galaxy A51 crucial features

Display

Screen quality, color accuracy, brightness

Type	Dynamic AMOLED	Super AMOLED
Size	6.8 inches	6.5 inches
Resolution	1440 x 3200 pixels	1080 x 2400 pixels
Aspect ratio	20:9	20:9
PPI	515 ppi	405 ppi
Refresh rate	120 Hz	60 Hz
Adaptive refresh rate	Yes	No
Max rated brightness	1500 nits	400 nits
HDR support	Yes, HDR10+	No
Screen protection	Gorilla Glass Victus	Corning Gorilla Glass 3
Screen-to-body ratio	89.8%	87.4%
Display features	- DCI-P3 - Always-On Display	- Always-On Display

RGB color space	-	98.8%
PWM	-	242 Hz
Response time	-	25 ms
Contrast	-	∞ Infinity

Height	165.1 mm (6.5 inches)	158.5 mm (6.24 inches)
Width	75.6 mm (2.98 inches)	73.6 mm (2.9 inches)
Thickness	8.9 mm (0.35 inches)	7.9 mm (0.31 inches)
Weight	227 g (8.01 oz)	172 g (6.07 oz)
Waterproof	IP68	No
Rear material	Glass	Plastic
Frame material	Metal	Plastic
Colors	Black, Silver, Gray, Blue	White, Black
Fingerprint scanner	Yes, in-display	Yes, in-display

Chipset	Samsung Exynos 2100	Samsung Exynos 9 Octa 9611
Max clock	2840 MHz	2300 MHz
CPU cores	8 (1 + 3 + 4)	8 (4 + 4)
Architecture	- 4 cores at 2.2 GHz: Cortex-A55 - 3 cores at 2.81 GHz: Cortex-A78 - 1 core at 2.91 GHz: Cortex-X1	- 4 cores at 1.7 GHz: Cortex-A53 - 4 cores at 2.3 GHz: Cortex-A73
Lithography process	5 nanometers	10 nanometers
Graphics	Mali-G78 MP14	Mali-G72 MP3
GPU shading units	896	54
GPU clock	854 MHz	850 MHz
FLOPS	~1530.4 GFLOPS	~91.8 GFLOPS

CPU	236566	69792
GPU	255535	55670
Memory	157504	60677
UX	183564	59872
Total score	833650	246594

Max surface temperature	40.8 °C	42.2 °C
Stability	69%	95%
Graphics test	31 FPS	4 FPS
Graphics score	5221	812

RAM size	12, 16 GB	4, 6 GB
Memory type	LPDDR5	LPDDR4X
Memory clock	2750 MHz	1866 MHz
Channels	2	2

Storage size	128, 256, 512 GB	64, 128 GB
Storage type	UFS 3.1	UFS 2.0
Memory card	No	MicroSD
Memory card max size	-	Up to 512 GB

Operating system	Android 11 (Can be upgraded to Android 13)	Android 10 (Can be upgraded to Android 13)
ROM	One UI 5.1	One UI 5.0
OS size	26.4 GB	23 GB

Capacity	5000 mAh	4000 mAh
Max charge power	25 W	15 W
Battery type	Li-Ion	Li-Po
Replaceable	No	No
Wireless charging	Yes (15 W)	No
Reverse charging	Yes, (wireless)	No
Fast charging	Yes (54% in 30 min)	Yes (40% in 35 min)
Full charging time	1:11 hr	1:50 hr

Battery life tests
Web browsing	10:13 hr	09:34 hr
Watching video	15:32 hr	11:29 hr
Gaming	05:26 hr	05:12 hr
Standby	98 hr	83 hr

Main camera
Matrix	108 megapixels	48 megapixels
Image resolution	12000 x 9000	8000 x 6000
Zoom	Optical, 10x	Digital
Flash	Dual LED	LED
Stabilization	Optical	Digital
8K video recording	Up to 24FPS	No
4K video recording	Up to 60FPS	Up to 30FPS
1080p video recording	Up to 60FPS	Up to 30FPS
Slow motion	960 FPS (720p)	960 FPS (720p)
Angle of widest lens	120°	120°
Lenses	4 (108 MP + 10 MP + 10 MP + 12 MP)	4 (48 MP + 12 MP + 5 MP + 5 MP)
Wide (main) lens	- 108 MP - Aperture: f/1.8 - Focal length: 26 mm - Pixel size: 0.8 micron - Sensor: 1/1.33", Samsung S5KHM3 (ISOCELL Plus CMOS) - Laser autofocus - Optical stabilization	- 48 MP - Aperture: f/2.0 - Focal length: 26 mm - Pixel size: 0.8 micron - Sensor: 1/2", Sony IMX582 (Exmor-RS CMOS) - Phase autofocus
Telephoto lens	- 10 MP - Aperture: f/4.9 - Focal length: 240 mm - Pixel size: 1.22 micron - Sensor: 1/2.65", Samsung S5K3J1 (ISOCELL CMOS) - Phase autofocus (Dual Pixel) - Optical stabilization	-
Ultra-wide lens	- 12 MP - Aperture: f/2.2 - Focal length: 13 mm - Pixel size: 1.4 micron - Sensor: 1/2.55", Sony IMX563 (Exmor-RS CMOS) - Phase autofocus (Dual Pixel)	- 12 MP - Aperture: f/2.2 - Focal length: 13 mm - Pixel size: 1.12 micron
Macro lens	-	- 5 MP - Aperture: f/2.4 - Focal length: 40 mm - Pixel size: 1.12 micron
Depth lens	-	- 5 MP - Aperture: f/2.2 - Pixel size: 1.12 micron - Sensor: 1/5.0" (CMOS)
Camera features	- Bokeh mode - Pro mode - RAW support	- Bokeh mode - Pro mode
Samples	Photo samples of Samsung Galaxy S21 Ultra from DxOMark	-

Selfie camera
Megapixels	40 megapixels	32 megapixels
Image resolution	7864 x 5200	6560 x 4928
Aperture	f/2.2	f/2.2
Focal length	26 mm	26 mm
Pixel size	0.7 microns	0.8 microns
Sensor type	ISOCELL CMOS	ISOCELL CMOS
Sensor size	1/2.65"	1/2.8"
Video resolution	2160p (4K) at 60 FPS	2160p (4K) at 30 FPS

Wi-Fi standard	Wi-Fi 6E (802.11 a/b/g/n/ac/ax)	Wi-Fi 5 (802.11 b/g/n/ac)
Wi-Fi features	- Dual Band - Wi-Fi MiMO - Wi-Fi Direct - Wi-Fi Hotspot - Wi-Fi Display	- Dual Band - Wi-Fi Direct - Wi-Fi Hotspot - Wi-Fi Display
Bluetooth version	5.2	5
Bluetooth features	LE, A2DP	PBAP/PAB, PAN, OPP, MAP, HSP, HID, HFP, DIP, AVRCP, A2DP
USB type	USB Type-C	USB Type-C
USB version	3.2	2
USB features	- Charging - USB-Storage mode - USB-Host mode - OTG	- Charging - USB-Storage mode - OTG
GPS	GPS, GLONASS, Beidou, Galileo	GPS, GLONASS, Beidou, Galileo
NFC *	Yes	Yes
Infrared port	No	No

Number of SIM *	2	2
Type of SIM card	Nano	Nano
Multi SIM mode	Standby	Standby
eSIM support *	Yes	No
Hybrid slot	No	No
LTE Cat *	24	12
5G support	Yes	No

Speakers	Stereo	Mono
Headphone audio jack	No	Yes
FM radio	No	Yes
Dolby Atmos	Yes	Yes

Category	Flagship	Mid-range
Announced	January 2021	December 2019
Release date	February 2021	December 2019
SAR (head)	0.71 W/kg	0.596 W/kg
SAR (body)	1.58 W/kg	1.45 W/kg
Sensors	- Hall-effect sensor - Barometer - Proximity sensor - Gyroscope - Accelerometer - Ambient light sensor - Compass - Fingerprint	- Proximity sensor - Gyroscope - Accelerometer - Ambient light sensor - Compass - Fingerprint

Samsung Galaxy S21 Ultra vs Galaxy A51

Samsung Galaxy S21 Ultra vs Galaxy A51

Key differences

Review

Value for money

Tests and specifications

Display

Design and build

Performance

Benchmarks

Memory

Software

Battery

Camera

DxOMark camera tests

Connectivity

Sound

Other

Conclusion