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Samsung Galaxy A51 (SM-A515F/DSM 128GB) vs Samsung Galaxy S21 Ultra (SM-G998U1 512GB)

Side by side comparison between Samsung Galaxy A51 vs Samsung Galaxy S21 Ultra phones, differences, pros, cons and full specifications. What's the better?

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Compare Samsung Galaxy S21 Ultra X Samsung Galaxy A51 (SM-A515F/DSM 128GB) 05Points
6.5"
AMOLED

1080x2400

48
MP

32mp

6GB
RAM

Octa-core

4000
mAh

(Non removable)

vs
33Points Samsung Galaxy S21 Ultra (SM-G998U1 512GB) Compare Samsung Galaxy A51 X
6.8"
AMOLED

1440x3200

108
MP

40mp

16GB
RAM

Octa-core

5000
mAh

(Non removable)

What's the better phone? Samsung Galaxy S21 Ultra (SM-G998U1 512GB)

The phonemore's choice is much more technical than personal. Therefore, you shouldn't only consider this. Our goal is to help you, but what's important to us may not be important to you. You decide which one is the best! Comment!

Galaxy A51 (SM-A515F/DSM 128GB)} 5 Advantages Samsung Galaxy A51 (SM-A515F/DSM 128GB) vs Galaxy S21 Ultra (SM-G998U1 512GB)} 33 Advantages Samsung Galaxy S21 Ultra (SM-G998U1 512GB)
+Until 1TB microSD, microSDXCAdvantage
More external storage for files using memory cards
vsNot supported
+172 grams (6.02 ounces)32%
Lighter
vs227 grams (7.95 ounces)
+7.9 millimeters (0.31 inches)13%
Thinner
vs8.9 millimeters (0.35 inches)
+ANT+Advantage
Sensors help you use the device
vsNot supported
+3.5mm jackAdvantage
Headsets with 3.5mm Jack size are more common and easy to find in stores
vsType-C reversible connector
2.3GHz 64bit Octa-core (10nm)vs+2.84GHz 64bit Octa-core (5nm)38%
More powerful processor, you can open your applications faster
6GB LPDDR4Xvs+16GB LPDDR5167%
More RAM memory. Typically more responsive and better for multitasking.
128GB (107GB available)vs+512GB (457GB available)3 times
More internal storage for applications and files
eMMC 5.1vs+UFS 3.1Advantage
Fastest write and read storage.
Plastic body, glass frontvs+Aluminum frame, glass front/backAdvantage
More resistant material
Not supportedvs+HDR10+Advantage
The HDR10+ display provides vibrant colors and more details
60Hzvs+120Hz100%
The display reproduces more frames per second because the frequency (Hertz) is higher, improves fluidity and tires your eyes less.
1080x2400 pixelsvs+1440x3200 pixels78%
Higher resolution screen
405 PPIvs+516 PPI27%
Crisper display of text, images and videos because it has more pixels per inch (ppi)
6.5"vs+6.8"5%
Larger screen
(quad camera) 48MP + 12MP + 5MP + 5MPvs+(quad camera) 108MP + 10MP + 10MP + 12MP100%
Higher resolution main camera
Only digital zoomvs+Digital and optical zoomAdvantage
The zoom allows for better focus and approach to take pictures
EIS: Digital stabilizationvs+OIS: Optical stabilizationAdvantage
Image stabilization prevents blurry photos and helps in recording motion video
1/2" inchesvs+1/1.33" inches50%
The larger sensor camera lets you take photos with better depth.
f/2.0 (aperture)vs+f/1.8 (aperture)11%
Diaphragm opening (Aperture) of the camera which has the smallest F number takes photos with better light exposure.
(front) 32MPvs+(front) 40MP25%
Higher resolution secondary camera to take pictures and selfies
4K UHD (3840x2160)vs+8K UHD (7680x4320)3 times
More image quality for recording videos with the primary camera
Android 13vs+Android 14Advantage
Android 14 is newer and safer
4G LTE-Avs+5G Sub6Advantage
The 5G Sub6 network is newer and faster
(4G LTE-A) 600 Mbpsvs+(5G Sub6) 5000 Mbps7 times
Faster for surfing the internet and download files
Not supportedvs+BarometerAdvantage
Sensors help you use the device
Virtual proximity sensorvs+Proximity sensorAdvantage
Sensors help you use the device
Not supportedvs+UWB (Ultra Wideband)Advantage
Sensors help you use the device
4000 mAhvs+5000 mAh25%
Battery - higher amperage (mAh) allows more device usage time, but it also depends on the hardware and use
15Wvs+25W67%
More power (watts) to charge the battery faster. Sometimes, the charger that comes with the device doesn't have the same power supported by the device. Check before you buy it.
Not supportedvs+Qi wireless charging (Qi/PMA)Advantage
Wireless charging is another way to charge the battery.
2 slots (Dual-SIM)
(dedicated slot)
vs+1 slot (Single-SIM) + e-SIM (Eletronic)Advantage
You can have more mobile carriers/operators on the same device.
802.11 a/b/g/n/ac [wifi5]vs+802.11 a/b/g/n/ac/ax [wifi6]Advantage
WiFi 802.11 a/b/g/n/ac/ax [wifi6] is newer and faster
Not supportedvs+DLNAAdvantage
With DLNA technology you can access and play media files on TV, tablet or DLNA compatible device.
5.0 + A2DP/LEvs+5.2 + A2DP/LEAdvantage
Bluetooth 5.2 + A2DP/LE is newer and faster
Not supportedvs+NFCAdvantage
NFC allows you to make payments by approach quickly and securely
USB 2.0 Type-C, USB OTG On-The-Govs+USB 3.2 Type-C, USB OTG On-The-GoAdvantage
Newer and faster USB version for transferring photos, mp3 or data.
Not supportedvs+IP68 certifiedAdvantage
Protection against water allows you talk to your friends in the rain, for example

19 Common items in both devices
Super AMOLED / Dynamic AMOLED
16 million
LED flash
PDAF: phase detection autofocus / PDAF: phase detection autofocus on both cameras
HDR photo on both cameras / HDR photo/video on both cameras
(front) 4K UHD (3840x2160)
Capacitive
+12 specs and more in the table below

Check the comparison table below for more items that are not evaluated in comparison score above.

Highlight differences Clear highlight

📱 Model features

Galaxy A51 (SM-A515F/DSM 128GB)Galaxy S21 Ultra (SM-G998U1 512GB)
ModelGalaxy A51 (SM-A515F/DSM 128GB)Galaxy S21 Ultra (SM-G998U1 512GB)
Other model namesSamsung Galaxy A51 SM-A515F/DSMGalaxy S21 Ultra 5G (SM-G998U1) Unlocked
Country or region availableKazakhstanRussia
Kazakhstan, Russia
USA
USA
BrandSamsungSamsung
Release date12/16/2019, Announced: 12/12/20191/29/2021, Announced: 1/14/2021
Depth7.9 millimeters (0.31 inches)8.9 millimeters (0.35 inches)
Size (width x height)73.6 x 158.5 millimeters (2.9 x 6.24 in)75.6 x 165.1 millimeters (2.98 x 6.5 in)
Weight172 grams (6.02 ounces)227 grams (7.95 ounces)
Build, materialsPlastic body, glass frontAluminum frame, glass front/back
Protection against water and othersNot supportedIP68 certified: water-resistant up to 1.5 meters for 30min and dust-resistant

📲 Display

Galaxy A51 (SM-A515F/DSM 128GB)Galaxy S21 Ultra (SM-G998U1 512GB)
Display typeSuper AMOLEDDynamic AMOLED
Screen size6.5" inches6.8" inches
Screen-to-body ratio~87.4% (screen-to-body ratio)~89.4% (screen-to-body ratio)
Display resolution1080x2400 pixels (20:9)1440x3200 pixels (20:9)
TouchscreenCapacitive MultitouchCapacitive Multitouch 10-points
Pixel density (dot pitch)405 PPI516 PPI
Colors16 million16 million
Scratch-resistant glassGorilla Glass 3Gorilla Glass Victus
Refresh rate60Hz120Hz
Display featuresAlways-On Display1500nits[peak]
HDR10+
Always-On Display

🤖 Operating System

Galaxy A51 (SM-A515F/DSM 128GB)Galaxy S21 Ultra (SM-G998U1 512GB)
System versionAndroid 10Android 11
Firmware updateAndroid 13Android 14
User InterfaceOne UI 2.5 / 3.1 / 4.1 / 5.0One UI 3.1 / 4.1 / 5.1 / 6.0

⚙️ Processor

Galaxy A51 (SM-A515F/DSM 128GB)Galaxy S21 Ultra (SM-G998U1 512GB)
Chipset64bit: Samsung Exynos 9611 (10nm)64bit: Qualcomm Snapdragon 888 (SM8350) (5nm)
CPUOcta-core, 2 processors:
4x 2.3GHz ARM Cortex-A73 (Quad-core)
4x 1.7GHz ARM Cortex-A53 (Quad-core)
Octa-core, 3 processors:
1x 2.84GHz Kryo 680 (Single-core)
3x 2.42GHz Kryo 680 (Triple-core)
4x 1.8GHz Kryo 680 (Quad-core)
GPU graphical controllerARM Mali-G72 MP3 (850MHz)Qualcomm Adreno 660 (840MHz)
Performance (benchmark)feature not registeredAnTuTu: 681099 (v8), 809165 (v9)
Geekbench: 3539 (v5.2)
GFXBench: 54fps (ES 3.1 onscreen)

💽 Memory and storage

Galaxy A51 (SM-A515F/DSM 128GB)Galaxy S21 Ultra (SM-G998U1 512GB)
RAM memory6GB LPDDR4X16GB LPDDR5
Internal storage128GB (107GB available)
eMMC 5.1
512GB (457GB available)
UFS 3.1
External storageUntil 1TB microSD, microSDXC
(dedicated slot)
Not supported

📶 Mobile networks

Galaxy A51 (SM-A515F/DSM 128GB)Galaxy S21 Ultra (SM-G998U1 512GB)
Dual-SIMDual-SIM Standby - Call active on one sim card
(dedicated slot)
Dual-SIM Standby - Call active on one sim card
SIM card2 slots (Dual-SIM)
nano-SIM (4FF)
1 slot (Single-SIM)
nano-SIM (4FF) + e-SIM
Maximum Download / Upload600/150 Mbps5000/1920 Mbps
Network technology2G, 3G, 4G2G, 3G, 4G, 5G
Frequency, bands Expand band details Collapse details
GSM MHz bandQuad-Band 850/900/1800/1900Quad-Band 850/900/1800/1900
Primary 2G networkGSM 850/900/1800/1900CDMA 800/1900, GSM 850/900/1800/1900
Primary 3G networkUMTS 850/900/1700/1900/2100CDMA2000 1xEV-DO
UMTS 850/900/1700/1900/2100
Primary 4G networkLTE Cat12/13 (1, 2, 3, 4, 5, 7, 8, 12, 13, 17, 20, 26, 28, 66)
TD-LTE (38, 40, 41)
VoLTE
LTE Cat20 (1, 2, 3, 4, 5, 7, 8, 12, 13, 14, 18, 19, 20, 25, 26, 28, 30, 66, 71)
TD-LTE (38, 39, 40, 41, 46, 48)
VoLTE
Primary 5G networkNot supportedSA/NSA/Sub6 (2, 5, 25, 41, 66, 71)
mmWave (260, 261)
Primary data networkGPRS, EDGE, UMTS, HSDPA, HSUPA, HSPA+, TD-LTE, LTE, LTE-AGPRS, EDGE, CDMA2000 EV-DO Rev 0, CDMA2000 EV-DO Rev A, UMTS, HSDPA, HSUPA, HSPA+, TD-LTE, LTE, LTE-A, SA/NSA, Sub6
Secondary 2G networkGSM 850/900/1800/1900CDMA 800/1900, GSM 850/900/1800/1900
Secondary 3G networkNot supportedCDMA2000 1xEV-DO
UMTS 850/900/1700/1900/2100
Secondary 4G networkNot supportedLTE Cat20 (1, 2, 3, 4, 5, 7, 8, 12, 13, 14, 18, 19, 20, 25, 26, 28, 30, 66, 71)
TD-LTE (38, 39, 40, 41, 46, 48)
VoLTE
Secondary data networkGPRS, EDGEGPRS, EDGE, CDMA2000 EV-DO Rev 0, CDMA2000 EV-DO Rev A, UMTS, HSDPA, HSUPA, HSPA+, TD-LTE, LTE, LTE-A, SA/NSA, Sub6

📷 Camera

Galaxy A51 (SM-A515F/DSM 128GB)Galaxy S21 Ultra (SM-G998U1 512GB)
Back camera (main camera)(quad camera)
48 megapixels
12MP ultrawide f/2.213mm1.12µm
5MP telephoto f/2.440mm
5MP depth f/2.21/5.0"1.12µm
(quad camera)
108 megapixels
10MP periscope telephoto f/4.9240mm1/3.24"1.22µmPDAFOIS10x-optical-zoom
10MP telephoto f/2.470mm1/3.24"1.22µmPDAFOIS3x-optical-zoom
12MP ultrawide f/2.213mm1/2.55"1.4µmPDAFSuper-Steady-video
Main camera resolution8000x6000 pixels12000x9000 pixels
Video recording (primary)4K UHD (3840x2160) 30 fps8K UHD (7680x4320) 24 fps
FlashLED flashLED flash
Focal aperturef/2.0 (aperture)f/1.8 (aperture)
Focal length26mm lens26mm lens
Sensor size1/2" inches1/1.33" inches
Pixel size0.8µm pixel1.8µm pixel
AutofocusPDAF: phase detection autofocusPDAF: phase detection autofocus on both cameras
Touch focusSupportedSupported
Image stabilizationEIS: Digital stabilizationOIS: Optical stabilization
ZoomOnly digital zoomDigital and optical zoom
Face/smile detectionFace detection, Smile detectionFace detection, Smile detection
BSI sensorNot supportedSupported
HDRHDR photo on both camerasHDR photo/video on both cameras
Camera extrasfeature not registered4K@60fps
1080p@240fps
720p@960fps

📸 Front camera

Galaxy A51 (SM-A515F/DSM 128GB)Galaxy S21 Ultra (SM-G998U1 512GB)
Front camera (secondary)32 megapixels40 megapixels
Front camera resolution6528x4896 pixels7296x5472 pixels
Video recording (secondary)4K UHD (3840x2160)4K UHD (3840x2160)
Front flashNot supportedNot supported
Focal aperturef/2.2 (aperture)f/2.2 (aperture)
Focal length26mm lens26mm lens
Sensor size1/2.8" inches1/2.8" inches
Pixel size0.8µm pixel0.7µm pixel

🔉 Sound and multimedia

Galaxy A51 (SM-A515F/DSM 128GB)Galaxy S21 Ultra (SM-G998U1 512GB)
LoudspeakerSupportedStereo sound
32-bit/384kHz
Dolby Atmos
Tuned by AKG
Active noise cancellation2 microphones or more2 microphones or more
RadioFM (RDS)FM
TVNot supportedNot supported
Video formatsMP4, H.265, H.264, H.263, XviD, MKVMP4, H.265, H.264, H.263, XviD, MKV
Audio formatsMP3, WAV, WMA, eAAC+, FLACMP3, WAV, WMA, eAAC+, FLAC

🔌 Connectivity

Galaxy A51 (SM-A515F/DSM 128GB)Galaxy S21 Ultra (SM-G998U1 512GB)
USBUSB 2.0 Type-C, USB OTG On-The-GoUSB 3.2 Type-C, USB OTG On-The-Go
Audio output3.5mm jackType-C reversible connector
TV outputNot supportedUSB Type-C (reversible)
Bluetooth5.0 + A2DP/LE5.2 + A2DP/LE
WiFi802.11 a/b/g/n/ac [wifi5] (2.4GHz, 5GHz) + MIMO
WiFi Direct, hotspot
802.11 a/b/g/n/ac/ax [wifi6] (2.4GHz, 5GHz) + MIMO
WiFi Direct, hotspot
DLNANot supportedSupported
GPSA-GPS, GeoTagging, GLONASS, GALILEO, BeiDouA-GPS, GeoTagging, GLONASS, GALILEO, BeiDou
NFCNot supportedSupported
Infrared portNot supportedNot supported

🧭 Sensors

Galaxy A51 (SM-A515F/DSM 128GB)Galaxy S21 Ultra (SM-G998U1 512GB)
SensorsAccelerometer
Ambient light sensor
ANT+
Compass
Face unlock
Fingerprint sensor (under display)
Gyroscope
Hall effect
Virtual proximity sensor
Accelerometer
Ambient light sensor
Barometer
Compass
Face unlock
Fingerprint sensor (under display)
Gesture
Gyroscope
Hall effect
Proximity sensor
UWB (Ultra Wideband)
Vibrating alertSupportedSupported

🔋 Battery

Galaxy A51 (SM-A515F/DSM 128GB)Galaxy S21 Ultra (SM-G998U1 512GB)
Battery typeLiPo: li-ion polymer (Non removable)LiPo: li-ion polymer (Non removable)
Battery capacity4000 mAh5000 mAh
Charger, watts15W Wired fast charging25W Wired fast charging
USB Power Delivery 3.0
Inductive / wireless chargingNot supported15W Qi wireless charging (Qi/PMA)
4.5W Reverse wireless charging
Talk time autonomyfeature not registeredfeature not registered
Standbyfeature not registeredfeature not registered

➕ Other features

Galaxy A51 (SM-A515F/DSM 128GB)Galaxy S21 Ultra (SM-G998U1 512GB)
Call controlVoice dialing, Voice recorderVoice dialing, Voice recorder, Voice commands
MessagingSMS (T9), MMS, E-mail, Push mailSMS (T9), MMS, E-mail, Push mail
Hands-free callingSupportedSupported
Video callingSupportedSupported
RingtonesPolyphonic and customizedPolyphonic and customized
Web browserHTML, XHTML, HTML5HTML, XHTML, HTML5
AntennaInternal antennaInternal antenna
Qwerty physical keyboardNot supportedNot supported
Miscellaneous• Colors: Prism, Crush Black, White, Blue, Pink• Colors: Phantom Black, Silver, Titanium, Navy, Brown
• Samsung Pay (Visa, MasterCard)
• Samsung DeX
• Stylus pen support

☢️ Radiation rate

Galaxy A51 (SM-A515F/DSM 128GB)Galaxy S21 Ultra (SM-G998U1 512GB)
SAR 1.6W/kg (USA, Mexico, etc.)feature not registered0.77W/kg (head), 1.02W/kg (body)
SAR 2W/kg (Europe, UK, etc.)0.369W/kg (head), 1.59W/kg (body)feature not registered
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