Samsung Galaxy S21 vs Samsung Galaxy S25 Ultra Specs Comparison

Display

Size
6.2-inch	6.8-inch
Resolution
2400 x 1080 px, 20:9 ratio, 424 PPI	3088 x 1440 px, 19.5:9 ratio, 501 PPI
Technology
Dynamic AMOLED	Dynamic AMOLED
Refresh rate
120Hz (adaptive)	120Hz
Screen-to-body
86.06 %	90.30 %
Peak brightness
1300 cd/m2 (nit)	2600 cd/m2 (nit)
Features
HDR support, Scratch-resistant glass (Corning Gorilla Glass Victus), Ambient light sensor, Proximity sensor	HDR support, Scratch-resistant glass (Corning Gorilla Glass Armor), Ambient light sensor, Proximity sensor

Hardware

System chip
Qualcomm Snapdragon 888 (5 nm)	Qualcomm Snapdragon 8 Gen 4
Processor
Octa-core, 1x 2.84GHz Kryo 680 + 3x 2.42GHz Kryo 680 + 4x 1.80GHz Kryo 680, 64-bit	Octa-core, 64-bit
GPU
Adreno 660	Yes
RAM
8GB (LPDDR5)	12GB
Internal storage
128GB (UFS 3.0), not expandable	256GB (UFS 4.0), not expandable
OS
Android (13, 12, 11), Samsung One UI	Android (14)
Device type
Smartphone	Smartphone

Battery

Capacity
4000 mAh	5000 mAh
Type
Li - Polymer, Not user replaceable	Li - Ion, Not user replaceable
Charging
Qualcomm Quick Charge 2.0, USB Power Delivery, Samsung Adaptive Fast Charging, Qi and Powermat wireless charging, Reverse wireless charging	Fast charging, Qi wireless charging, Reverse wireless charging
Max charge speed
Wired: 25.0W Wireless: 15.0W	Wired: 45.0W Wireless: 15.0W

PhoneArena Battery Tests

Battery Life Estimate

4h 28min

Browsing

7h 47min

Video

7h 36min

Gaming

7h 9min

Battery Life Estimate

Untested

Browsing

Untested

Video

Untested

Gaming

Untested

Find out more details about battery and charging for all phones we have tested on our PhoneArena Battery Score page.

Camera

Rear
Triple camera	Quad camera
Main camera
12 MP (OIS, PDAF) Specifications: Aperture size: F1.8 Focal length: 26 mm Sensor size: 1/1.76" Pixel size: 1.8 μm	200 MP (OIS, Laser and PDAF) Specifications: Aperture size: F1.7 Focal length: 24 mm Sensor size: 1/1.3" Pixel size: 0.6 μm
Second camera
64 MP (Telephoto, OIS, PDAF) Specifications: Aperture size: F2.0 Focal Length: 29 mm Sensor size: 1/1.7" Pixel size: 0.8 μm	50 MP (Telephoto, Periscope, OIS, PDAF) Specifications: Optical zoom: 5.0x Aperture size: F3.4 Focal Length: 111 mm
Third camera
12 MP (Ultra-wide, Autofocus) Specifications: Aperture size: F2.2 Focal Length: 13 mm Sensor size: 1/2.55" Pixel size: 1.4 μm	10 MP (Telephoto, OIS, PDAF) Specifications: Optical zoom: 3.0x Aperture size: F2.4 Focal Length: 67 mm Sensor size: 1/3.52" Pixel size: 1.12 μm
Fourth camera
	12 MP (Ultra-wide, PDAF) Specifications: Aperture size: F2.2 Focal Length: 13 mm Sensor size: 1/2.55" Pixel size: 1.4 μm
Flash
LED	LED
Video recording
7680x4320 (8K UHD) (24 fps), 3840x2160 (4K UHD) (60 fps), 1920x1080 (Full HD) (240 fps), 1280x720 (HD) (960 fps) Features: OIS, HDR, Hyperlapse, Continuous autofocus, Video light, EIS	7680x4320 (8K UHD) (30 fps), 3840x2160 (4K UHD) (120 fps), 1920x1080 (Full HD) (240 fps)
Front
10 MP (PDAF, HDR), Video capture: 3840x2160 (4K UHD) (60 fps)	12 MP, Video capture: 3840x2160 (4K UHD) (60 fps)

PhoneArena Camera Tests

N/A

Overall

N/A

Photo

N/A

Video

N/A

Overall

N/A

Photo

N/A

Video

Find out more details about photo and video scores for all phones we have tested on our PhoneArena Camera Score page.

Design

Dimensions
5.97 x 2.80 x 0.31 inches (151.7 x 71.2 x 7.9 mm)	6.41 x 3.06 x 0.32 inches (162.82 x 77.65 x 8.25 mm)
Weight
6.03 oz(171.0 g)
Materials
Back: Plastic Frame: Aluminum	Back: Glass (Corning Gorilla Glass) Frame: Titanium
Resistance
Water, Dust; IP68	Yes; IP68
Biometrics
2D Face unlock, Ultrasonic in-screen fingerprint	Ultrasonic in-screen fingerprint
Features
	Stylus
Keys
Right: Volume control, Lock/Unlock key	Right: Volume control, Lock/Unlock key
Colors
Phantom pink, Violet, Gray, White

Cellular

5G
Bands n2, n5, n12, n25, n41, n66, n71, n77, n260, n261, SA, NSA, Sub-6, mmWave	Bands mmWave, 5G Ready
4G (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), 18(800 Lower), 19(800 Upper), 20(800 DD), 25(1900+), 26(850+), 28(700 APT), 30(2300 WCS), 66(AWS-3), 71(600)
4G (TDD)
Bands 38(2600), 39(1900+), 40(2300), 41(2600+), 46, 48(3600)
3G
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, UMTS	LTE-A, HSDPA+ (4G) 42.2 Mbit/s
SIM type
Nano SIM	Dual Nano SIM + eSIM

Multimedia

Headphones
No 3.5mm jack	No 3.5mm jack
Speakers
Earpiece, Multiple speakers	Earpiece, Multiple speakers
Features
32-Bit DAC, Dolby Atmos, aptX, Dolby Digital, Dolby Digital Plus
Screen mirroring
Wireless screen share	Wireless screen share
Radio
FM, Stereo, RDS
Additional microphone(s)
Noise cancellation, Video recording	Noise cancellation

Connectivity & Features

Bluetooth
5.0	5.3
Wi-Fi
802.11 a,b,g,n,ac,ax(Wi-Fi 6),dual-band MIMO, Wi-Fi Direct, Hotspot	802.11 a,b,g,n,ac,ax(Wi-Fi 6),Wi-Fi 7,Wi-Fi 6E Wi-Fi Direct, Hotspot
USB
Type-C (reversible), USB 3.2, Features: Charging, Headphones port, OTG, Video out	Type-C (reversible), USB 3.2, Features: Charging, OTG
Hearing aid compatible
M3/T3
Location
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), Barometer	Accelerometer, Gyroscope, Compass, Barometer
Other
NFC, ANT+	NFC, Ultra Wideband (UWB)

Regulatory Approval

FCC approval
Date approved: Dec 08, 2020 FCC ID value: A3LSMG991U
Measured SAR
Head: 0.36 W/kg Body: 1.08 W/kg Simultaneous Transmission: 3.96 W/kg Wireless Router: 1.09 W/kg Phablet: 2.49 W/kg

Buyers information

Price
$ 800
In The Box
C to C Data Cable, Ejection Pin

Availability

Officially announced
Jan 14, 2021

Links

Full specifications
Samsung Galaxy S21 Specs	Samsung Galaxy S25 Ultra Specs
PhoneArena Review
Samsung Galaxy S21 Review
User Reviews
Samsung Galaxy S21 User Reviews