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Xiaomi Poco X3 Pro (J20SI 128GB) vs Samsung Galaxy S21 Ultra (SM-G998U1 512GB)

Side by side comparison between Xiaomi Poco X3 Pro 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 Xiaomi Poco X3 Pro (J20SI 128GB) 06Points
6.67"
IPS

1080x2400

48
MP

20mp

6GB
RAM

Octa-core

5160
mAh

(Non removable)

vs
31Points Samsung Galaxy S21 Ultra (SM-G998U1 512GB) Compare Xiaomi Poco X3 Pro 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!

Poco X3 Pro (J20SI 128GB)} 6 Advantages Xiaomi Poco X3 Pro (J20SI 128GB) vs Galaxy S21 Ultra (SM-G998U1 512GB)} 31 Advantages Samsung Galaxy S21 Ultra (SM-G998U1 512GB)
+Until 1TB microSD, microSDXCAdvantage
More external storage for files using memory cards
vsNot supported
+215 grams (7.53 ounces)6%
Lighter
vs227 grams (7.95 ounces)
+Dual-LED flashAdvantage
The Dual-LED flash helps in dark places or in low light
vsLED flash
+5160 mAh3%
Battery - higher amperage (mAh) allows more device usage time, but it also depends on the hardware and use
vs5000 mAh
+33W32%
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.
vs25W
+3.5mm jackAdvantage
Headsets with 3.5mm Jack size are more common and easy to find in stores
vsType-C reversible connector
2.96GHz 64bit Octa-core (7nm)vs+2.84GHz 64bit Octa-core (5nm)8%
More powerful processor, you can open your applications faster
6GB LPDDR4Xvs+16GB LPDDR5167%
More RAM memory. Typically more responsive and better for multitasking.
128GB (106GB available)vs+512GB (457GB available)3 times
More internal storage for applications and files
9.4 millimeters (0.37 inches)vs+8.9 millimeters (0.35 inches)6%
Thinner
Plastic body, glass frontvs+Aluminum frame, glass front/backAdvantage
More resistant material
TFT IPS LCDvs+Dynamic AMOLEDAdvantage
Dynamic AMOLED display is brighter and more vivid
HDR10vs+HDR10+Advantage
The HDR10+ display provides vibrant colors and more details
1080x2400 pixelsvs+1440x3200 pixels78%
Higher resolution screen
395 PPIvs+516 PPI31%
Crisper display of text, images and videos because it has more pixels per inch (ppi)
6.67"vs+6.8"2%
Larger screen
(quad camera) 48MP + 8MP + 2MP + 2MPvs+(quad camera) 108MP + 10MP + 10MP + 12MP133%
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
Not supportedvs+BSI sensorAdvantage
The BSI sensor allows the entry of more light generating photos with more detail and brightness
1/2" inchesvs+1/1.33" inches50%
The larger sensor camera lets you take photos with better depth.
(front) 20MPvs+(front) 40MP101%
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
(front) Full HD (1920x1080)vs+(front) 4K UHD (3840x2160)3 times
More image quality for recording videos with the secondary camera
Android 13vs+Android 15Advantage
Android 15 is newer and safer
4G LTE-Avs+5G Sub6Advantage
The 5G Sub6 network is newer and faster
(4G LTE-A) 800 Mbpsvs+(5G Sub6) 5000 Mbps5 times
Faster for surfing the internet and download files
Not supportedvs+BarometerAdvantage
Sensors help you use the device
Not supportedvs+UWB (Ultra Wideband)Advantage
Sensors help you use the device
Not supportedvs+Qi wireless charging (Qi/PMA)Advantage
Wireless charging is another way to charge the battery.
2 slots (Dual-SIM)
(hybrid slot/shares the same microSD 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.
IP53 certifiedvs+IP68 certifiedAdvantage
Protection against water allows you talk to your friends in the rain, for example

25 Common items in both devices
UFS 3.1
120Hz
16 million
PDAF: phase detection autofocus / PDAF: phase detection autofocus on both cameras
HDR photo on both cameras / HDR photo/video on both cameras
f/1.8 (aperture)
Capacitive
+18 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

Xiaomi Poco X3 Pro (J20SI 128GB)Galaxy S21 Ultra (SM-G998U1 512GB)
ModelPoco X3 Pro (J20SI 128GB)Galaxy S21 Ultra (SM-G998U1 512GB)
Other model namesPOCO X3 Pro M2102J20SI (128GB+6GB RAM)Galaxy S21 Ultra 5G (SM-G998U1) Unlocked
Country or region availableIndia
India
USA
USA
BrandXiaomiSamsung
Release date3/24/2021, Announced: 3/22/20211/29/2021, Announced: 1/14/2021
Depth9.4 millimeters (0.37 inches)8.9 millimeters (0.35 inches)
Size (width x height)76.8 x 165.3 millimeters (3.02 x 6.51 in)75.6 x 165.1 millimeters (2.98 x 6.5 in)
Weight215 grams (7.53 ounces)227 grams (7.95 ounces)
Build, materialsPlastic body, glass frontAluminum frame, glass front/back
Protection against water and othersIP53 certified: protection against dust and splashingIP68 certified: water-resistant up to 1.5 meters for 30min and dust-resistant

📲 Display

Xiaomi Poco X3 Pro (J20SI 128GB)Galaxy S21 Ultra (SM-G998U1 512GB)
Display typeTFT IPS LCDDynamic AMOLED
Screen size6.67" inches6.8" inches
Screen-to-body ratio~84.6% (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)395 PPI516 PPI
Colors16 million16 million
Scratch-resistant glassGorilla Glass 6Gorilla Glass Victus
Refresh rate120Hz120Hz
Display features450nits[typ]
HDR10
1500nits[peak]
HDR10+
Always-On Display

🤖 Operating System

Xiaomi Poco X3 Pro (J20SI 128GB)Galaxy S21 Ultra (SM-G998U1 512GB)
System versionAndroid 11Android 11
Firmware updateAndroid 13Android 15
User InterfaceMIUI 12.5 / 13 / 14One UI 3.1 / 4.1 / 5.1 / 6.0 / 7.0

⚙️ Processor

Xiaomi Poco X3 Pro (J20SI 128GB)Galaxy S21 Ultra (SM-G998U1 512GB)
Chipset64bit: Qualcomm Snapdragon 860 (SM8150-AC) (7nm)64bit: Qualcomm Snapdragon 888 (SM8350) (5nm)
CPUOcta-core, 3 processors:
1x 2.96GHz Kryo 485 Gold (Single-core)
3x 2.42GHz Kryo 485 Gold (Triple-core)
4x 1.78GHz Kryo 485 Silver (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 controllerQualcomm Adreno 640 (250-672MHz)Qualcomm Adreno 660 (840MHz)
Performance (benchmark)AnTuTu: 483527 (v8)
Geekbench: 2574 (v5.1)
GFXBench: 38fps (ES 3.1 onscreen)
AnTuTu: 681099 (v8), 809165 (v9)
Geekbench: 3539 (v5.2)
GFXBench: 54fps (ES 3.1 onscreen)

💽 Memory and storage

Xiaomi Poco X3 Pro (J20SI 128GB)Galaxy S21 Ultra (SM-G998U1 512GB)
RAM memory6GB LPDDR4X16GB LPDDR5
Internal storage128GB (106GB available)
UFS 3.1
512GB (457GB available)
UFS 3.1
External storageUntil 1TB microSD, microSDXC
(hybrid slot/shares the same SIM-2 slot)
Not supported

📶 Mobile networks

Xiaomi Poco X3 Pro (J20SI 128GB)Galaxy S21 Ultra (SM-G998U1 512GB)
Dual-SIMDual-SIM Standby - Call active on one sim card
(hybrid slot/shares the same microSD 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 / Upload800/150 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 Cat15/13 (1, 2, 3, 4, 5, 7, 8, 20, 28)
TD-LTE (38, 40, 41)
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 networkUMTS 850/900/1700/1900/2100CDMA2000 1xEV-DO
UMTS 850/900/1700/1900/2100
Secondary 4G networkLTE Cat15/13 (1, 2, 3, 4, 5, 7, 8, 20, 28)
TD-LTE (38, 40, 41)
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
Secondary 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

📷 Camera

Xiaomi Poco X3 Pro (J20SI 128GB)Galaxy S21 Ultra (SM-G998U1 512GB)
Back camera (main camera)(quad camera)
48 megapixels
8MP ultrawide f/2.2119°1.0µm
2MP macro f/2.4
2MP depth f/2.4
(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
FlashDual-LED flashLED flash
Focal aperturef/1.8 (aperture)f/1.8 (aperture)
Focal lengthfeature not registered26mm (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 extras1080p@960fps4K@60fps
1080p@240fps
720p@960fps

📸 Front camera

Xiaomi Poco X3 Pro (J20SI 128GB)Galaxy S21 Ultra (SM-G998U1 512GB)
Front camera (secondary)20 megapixels40 megapixels
Front camera resolution5184x3840 pixels7296x5472 pixels
Video recording (secondary)Full HD (1920x1080)4K UHD (3840x2160)
Front flashNot supportedNot supported
Focal aperturef/2.2 (aperture)f/2.2 (aperture)
Focal lengthfeature not registered26mm (lens)
Sensor size1/3.4" inches1/2.8" inches
Pixel size0.8µm pixel0.7µm pixel

🔉 Sound and multimedia

Xiaomi Poco X3 Pro (J20SI 128GB)Galaxy S21 Ultra (SM-G998U1 512GB)
LoudspeakerStereo sound with dual speakersStereo sound
32-bit/384kHz
Dolby Atmos
Tuned by AKG
Active noise cancellation2 microphones or more3 microphones
RadioFMFM
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

Xiaomi Poco X3 Pro (J20SI 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 outputUSB Type-C (reversible)USB 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 portSupportedNot supported

🧭 Sensors

Xiaomi Poco X3 Pro (J20SI 128GB)Galaxy S21 Ultra (SM-G998U1 512GB)
SensorsAccelerometer
Ambient light sensor
Compass
Face unlock
Fingerprint sensor (side-mounted)
Gyroscope
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

Xiaomi Poco X3 Pro (J20SI 128GB)Galaxy S21 Ultra (SM-G998U1 512GB)
Battery typeLiPo: li-ion polymer (Non removable)LiPo: li-ion polymer (Non removable)
Battery capacity5160 mAh5000 mAh
Charger, watts33W 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

Xiaomi Poco X3 Pro (J20SI 128GB)Galaxy S21 Ultra (SM-G998U1 512GB)
Call controlVoice dialing, Voice recorder, Voice commandsVoice 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: Phantom Black, Frost Blue, Metal Bronze
• Silicone Case included
• Cooling up to 6 °C
• LiquidCool 1.0 Plus
• Colors: Phantom Black, Silver, Titanium, Navy, Brown
• Samsung Pay (Visa, MasterCard)
• Samsung DeX
• Stylus pen support

☢️ Radiation rate

Xiaomi Poco X3 Pro (J20SI 128GB)Galaxy S21 Ultra (SM-G998U1 512GB)
SAR 1.6W/kg (USA, Mexico, etc.)0.99W/kg (head), 0.67W/kg (body)0.77W/kg (head), 1.02W/kg (body)
SAR 2W/kg (Europe, UK, etc.)0.57W/kg (head), 0.9W/kg (body)feature not registered
X

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