Xiaomi MI 9 vs. Samsung Galaxy S21 Ultra 5G

Phone Comparison, Reviews and Tests

Side by side comparison and review of Xiaomi MI 9 and Samsung Galaxy S21 Ultra 5G. Compare sizes, cameras, batteries, memory capacities and other key specifications and features to simplify the choice of your perfect phone. Our goal is to make it easier for you to decide on the phone that will best meet your expectations by revealing the main differences between the products.

Phone Specifications Comparison

Xiaomi MI 9 vs. Samsung Galaxy S21 Ultra 5G Comparison Chart
DESIGN AND DIMENSIONS Xiaomi MI 9 Samsung Galaxy S21 Ultra 5G
Product Type Smartphone Smartphone
Manufacturer Model Number - SM-G998B/DS
Form Factor Touch Touch
Height 157.5 mm 161.5 mm Samsung Galaxy S21 Ultra 5G has greater height than Xiaomi MI 9.
Width 74.67 mm 75.6 mm Samsung Galaxy S21 Ultra 5G has greater width than Xiaomi MI 9.
Depth 7.61 mm 8.9 mm Xiaomi MI 9 is narrower than Xiaomi MI 9.
Weight 173 g 227 g Xiaomi MI 9 is lighter than Xiaomi MI 9.
Body Colour Ocean blue | Piano black Phantom silver | Phantom black | Phantom navy | Phantom brown | Phantom titanium
Body Material Curved glass -
Protection - Dustproof, splashproof, water-resistant
Waterproof (Water-resistant) - Yes Samsung Galaxy S21 Ultra 5G is waterproof.
IP rating - IP68
SAR Value 1.301 W/kg (body), 1.389 W/kg (head) 1.58 W/kg (body), 0.714 W/kg (head), 2.56 W/kg (limb)
Connector Type USB Type-C - 24 pin USB-C USB Type-C - 24 pin USB-C
SIM Card Type (Size) Nano SIM Nano SIM, Electronic SIM card (e-SIM)
SIM Card Qty Dual-SIM Dual-SIM
DISPLAY Xiaomi MI 9 Samsung Galaxy S21 Ultra 5G
Display Type OLED display OLED display
Display Technology AMOLED Infinity-O Dynamic AMOLED 2X
Screen Size (Display Size) 6.39" 6.8" Samsung Galaxy S21 Ultra 5G has larger screen size than Xiaomi MI 9.
Screen Resolution (Display Resolution) 2340 x 1080 pixels 3200 x 1440 pixels Samsung Galaxy S21 Ultra 5G has better screen resolution than Xiaomi MI 9.
Display Format Full HD+ QHD+
Pixel Density 403 ppi 515 ppi Samsung Galaxy S21 Ultra 5G has better pixel density than Xiaomi MI 9.
Max Brightness 600 cd/m² -
Colour Depth - 16.7 million colours
Contrast Ratio 60000:1 -
HDR Yes Yes Both phones have HDR.
HDR Technology HDR10 HDR10+
Display Enhancement Technology Sunshine mode 2.0 Eye Comfort Shield
Display Refresh Rate - 120 Hz
Display Features Always-on display, Reading mode, Colour temperature adjustment, night mode, Wide Colour Gamut (WCG) Edge Screen, AOD(Always On Display)
Display Protection (Screen Protector) Fingerprint-resistant coating, Corning Gorilla Glass 6 (scratch resistant glass), oil protective coating Corning Gorilla Glass Victus (scratch resistant glass)
PROCESSOR Xiaomi MI 9 Samsung Galaxy S21 Ultra 5G
Processor Type (CPU) Qualcomm Snapdragon 855 Samsung Exynos 2100
Clock Speed 2.84 GHz 2.9 GHz Samsung Galaxy S21 Ultra 5G has higher clock speed than Xiaomi MI 9.
Processor Core Qty 8-core 8-core Both phones have the same number of phone cores.
64-bit Architecture Yes - Xiaomi MI 9 has 64-bit architecture.
Graphics System (GPU) Qualcomm ADRENO 640 Mali-G78 MP14
MEMORY Xiaomi MI 9 Samsung Galaxy S21 Ultra 5G
RAM LPDDR4X SDRAM - 6 GB LPDDR5 SDRAM - 12 GB Samsung Galaxy S21 Ultra 5G has more RAM than Xiaomi MI 9.
Internal Memory Size (Storage Capacity) 64 GB 128 GB Samsung Galaxy S21 Ultra 5G has more internal memory than Xiaomi MI 9.
User Memory - 101.7 GB
CAMERA Xiaomi MI 9 Samsung Galaxy S21 Ultra 5G
MAIN CAMERA
Number of Main Cameras 3 4
Sensor Resolution 48 Megapixel 12 Megapixel Xiaomi MI 9 has better camera resolution than Samsung Galaxy S21 Ultra 5G.
Sensor Name Sony Exmor RS IMX586 sensor -
Lens Type Ultra wide-angle lens Ultra wide-angle lens
Lens Aperture F/1.75 F/2.2 Xiaomi MI 9 has better lens aperture than Xiaomi MI 9.
Field of View (FoV) - 120 degree(s)
Pixel Size 0.8 μm 1.4 μm Samsung Galaxy S21 Ultra 5G has larger camera pixel size than Xiaomi MI 9.
Optical Image Stabiliser (OIS) - Optical Image Stabiliser (OIS) Samsung Galaxy S21 Ultra 5G has optical stabilisation.
Focus Adjustment Automatic Automatic
Laser Auto Focus Yes Yes
Optical Zoom 2x 3x Samsung Galaxy S21 Ultra 5G has better optical zoom than Xiaomi MI 9.
Digital Zoom 10x 100x Samsung Galaxy S21 Ultra 5G has better digital zoom than Xiaomi MI 9.
Self-Timer Delay - Yes
Special Effects HDR Face retouch, Grid Line
HDR Mode - Auto HDR mode
Camera Modes Burst mode, Panorama, portrait mode, AI Beautify, Smart ultra-wide angle mode, Ultra nightscape mode, Photo timer, Level display, Custom watermark, Full body portrait mode, Moon mode Panorama, Slow motion mode, Pro mode, HYPERLAPSE, Super Slow-mo, Flowers, Greenery, Trees, Sky, Beaches, Watersides, Snow, Backlit, Text, Food, Face, Baby, Person, Dog, Cat, People, Sunset, Sunrise, City, Waterfall, Scenery, Stage, Vehicles, Drinks, Animal, Shoes, Indoor, Clothes, Night view, Night, Motion Photo, Mountain, Single Take, Pro Video, Director's View
Face Recognition (Face ID) Face recognition - Xiaomi MI 9 has face detection.
Light Source Dual flash High CRI LED flash
Still Image Resolutions 8000 x 6000 -
Video Resolutions 1920 x 1080 (1080p) at 30 fps, 1920 x 1080 (1080p) at 60 fps, 1280 x 720 (720p) at 30 fps, Slo-mo video 1920 x 1080 (1080p) at 120 fps, Slo-mo video 1280 x 720 (720p) at 240 fps, 3840 x 2160 (4K) at 30 fps, Slo-mo video 1280 x 720 (720p) at 120 fps, 3840 x 2160 (4K) at 60 fps, Slo-mo video 1920 x 1080 (1080p) at 240 fps, Slo-mo video 1920 x 1080 (1080p) at 960 fps, Slo-mo video 1280 x 720 (720p) at 960 fps 1920 x 1080 (1080p) at 60 fps, 1280 x 720 (720p) at 30 fps, 3840 x 2160 (4K) at 60 fps, Super slow motion video 1280 x 720 (720p) at 960 fps, Slo-mo video 1920 x 1080 (1080p) at 240 fps, 7680 x 4320 (UHD 8K) at 24fps, Hyperlapse 4K video support at 30 fps, Super Steady 1080p video support at 60 fps
Camera Features (Functions) Sapphire crystal lens cover, Phase Detect Auto-Focus (PDAF), Dynamic photos, video stabilisation, Contrast Auto-Focus, AI scene detection, AI studio lighting, Video Beautify, AI Triple camera, 960 fps Smart audio pairing, AI lens flare, AI high resolution photos, Portrait mode background blur adjustment, Ultra wide-angle edge distortion correction, Group photo face correction, Portrait mode background blurring, Motion tracking, Quick motion Playback zoom, blink detection, VDIS (Video Digital Image Stabilisation), Tracking AF, Video location tags, Scene Optimiser, Flaw detection, Shot suggestions, blur detection, HDR10+ recording, Super steady, Quick Measure, Zoom-In Mic, Space Zoom, Take 33MP still photos while playing 8K video, Hybrid Optic Zoom 3x, Super Resolution Zoom up to 30x, Digital zoom up to 12x for video
SECOND CAMERA
Sensor Resolution (2nd Camera) 12 Megapixel 108 Megapixel Samsung Galaxy S21 Ultra 5G has better second camera resolution than Xiaomi MI 9.
Sensor Size (2nd Camera) - 1/1.33"
Lens Type (2nd Camera) Telephoto lens Wide-angle lens
Lens Aperture (2nd Camera) F/2.2 F/1.8 Samsung Galaxy S21 Ultra 5G has better second camera lens aperture than Xiaomi MI 9.
Field of View (2nd Camera) - 83 degree(s)
Pixel Size (2nd Camera) 1 μm 0.8 μm Xiaomi MI 9 has larger second camera pixel size than Samsung Galaxy S21 Ultra 5G.
Camera Features (2nd Camera) Macro photography Phase Detect Auto-Focus (PDAF), OIS (Optical Image Stabilisation)
THIRD CAMERA
Sensor Resolution (3rd Camera) 16 Megapixel 10 Megapixel Xiaomi MI 9 has higher resolution third camera than Samsung Galaxy S21 Ultra 5G.
Lens Type (3rd Camera) Ultra wide-angle lens Telephoto lens
Lens Aperture (3rd Camera) F/2.2 F/2.4 Xiaomi MI 9 has better third camera lens aperture than Xiaomi MI 9.
Field of View (3rd Camera) - 35 degree(s)
Pixel Size (3rd Camera) 1 μm 1.22 μm Samsung Galaxy S21 Ultra 5G has larger third camera pixel size than Xiaomi MI 9.
Camera Features (3rd Camera) - Dual Pixel AF
FOURTH CAMERA
Sensor Resolution (4th Camera) - 10 Megapixel
Lens Type (4th Camera) - Telephoto lens
Lens Aperture (4th Camera) - F/4.9
Field of View (4th Camera) - 10 degree(s)
Pixel Size (4th Camera) - 1.22 μm
Camera Features (4th Camera) - Dual Pixel AF
FRONT CAMERA
Number of Front Cameras 1 1
Sensor Resolution (Front) 20 Megapixel 40 Megapixels Samsung Galaxy S21 Ultra 5G has better front camera resolution than Xiaomi MI 9.
Lens Aperture (Front) F/2.0 F/2.2 Xiaomi MI 9 has better front lens aperture than Xiaomi MI 9.
Field of View (Front) - 80 degree(s)
Pixel Size (Front) 0.9 μm 0.7 μm Xiaomi MI 9 has larger front camera pixel size than Samsung Galaxy S21 Ultra 5G.
Focus Adjustment - Automatic
Special Effects (Front) HDR, Magic mirror -
Camera Modes (Front) AI portrait mode, AI Beautify, AI makeup -
Face Recognition (Face ID) Face recognition - Xiaomi MI 9 has face detection.
Video Resolutions (Front) 1920 x 1080 (1080p) at 30 fps, 1280 x 720 (720p) at 30 fps -
Camera Features (Front) Self-timer, age recognition, Video Beautify, AI scene detection, AI studio lighting, Eye light, AI feature adjustment, AI lens flare Phase Detect Auto-Focus (PDAF)
BATTERY AND CHARGING Xiaomi MI 9 Samsung Galaxy S21 Ultra 5G
Battery Capacity (Battery Size) 3300 mAh 5000 mAh Samsung Galaxy S21 Ultra 5G has larger battery capacity than Xiaomi MI 9.
Fast Charging Technology Qualcomm Quick Charge 4.0+ Qualcomm Quick Charge 2.0, Adaptive Fast Charging, Samsung Super Fast Charging, Power Delivery 3.0 Both phones have fast charging technology.
Wireless Charging - Yes Samsung Galaxy S21 Ultra 5G can be charged wirelessly.
Wireless Charging Standards WPC, Qi WPC, Qi, Fast Wireless Charging 2.0, Wireless PowerShare
Talk Time - 2460 minutes
Run Time Details - Talk (4G): up to 2460 min
Active online usage (LTE): up to 18 hrs
Active online usage (Wi-Fi): up to 18 hrs
Playback (wireless video): up to 22 hrs
Playback (wireless audio): up to 81 hrs
CELLULAR Xiaomi MI 9 Samsung Galaxy S21 Ultra 5G
Technology CDMA2000 1X / GSM / WCDMA (UMTS) / TD-SCDMA WCDMA (UMTS) / GSM
Mobile Broadband Generation 4G 5G Samsung Galaxy S21 Ultra 5G has more advanced generation mobile network.
Operating System - Android 11
User Interface MIUI 10 -
Intelligent Assistant Google Assistant Bixby
Payment Technology Android Pay Samsung Pay
Navigation GPS, A-GPS, GLONASS, BeiDou, Galileo GPS, GLONASS, BeiDou, Galileo
COMMUNICATIONS Xiaomi MI 9 Samsung Galaxy S21 Ultra 5G
Data Transmission GPRS, EDGE, EV-DO, HSDPA, HSUPA, HSPA+, VoLTE, FDD-LTE, TDD-LTE FDD-LTE, TDD-LTE, 5G NR FR1
2G Band - 850 GSM, 900 GSM, 1800 GSM, 1900 GSM
3G UMTS Band Band 1, Band 2, Band 4, Band 5, Band 8 Band 1, Band 2, Band 4, Band 5, Band 8
3G UMTS Frequency 2100, 1900, 1700, 850, 900 2100, 1900, 1700, 850, 900
4G LTE Band Band 1, Band 2, Band 3, Band 4, Band 5, Band 7, Band 8, Band 12, Band 20, Band 28, Band 38, Band 39, Band 40 Band 1, Band 2, Band 3, Band 4, Band 5, Band 7, Band 8, Band 12, Band 13, Band 17, Band 18, Band 19, Band 20, Band 25, Band 26, Band 28, Band 32, Band 38, Band 39, Band 40, Band 41, Band 66
4G LTE Frequency FDD 2100, FDD 1900 PCS, FDD 1800+, FDD 1700 - 2110 AWS, FDD 850, FDD 2600, FDD 900, FDD 700a, FDD 800 DD, FDD 700 APT, TDD 2600, TDD 1900, TDD 2300 FDD 2100, FDD 1900 PCS, FDD 1800+, FDD 1700 - 2110 AWS, FDD 850, FDD 2600, FDD 900, FDD 700a, FDD 700c, FDD 700b, FDD 800 lower, FDD 800 upper, FDD 800 DD, FDD 1900+, FDD 850+, FDD 700 APT, FDD 1500 L, TDD 2600, TDD 1900, TDD 2300, TDD 2500, FDD 1700 - 2110 AWS-3
5G NR Band - N1, n3, n5, n7, n8, n20, n28, n38, n41, n66, n77, n78, n40
5G NR Frequency - FDD 2100, FDD 1800, FDD 850, FDD 2600, FDD 900, FDD 800, FDD 700APT, TDD TD 2600, TDD TD 2500, FDD AWS-3, TDD TD 3700, TDD TD 3500, TDD 2300
Wireless Interface IEEE 802.11a/b/g/n/ac IEEE 802.11a/b/g/n/ac/ax
Bluetooth Bluetooth 5.0 Bluetooth 5.2
NFC Yes Yes Both phones have an NFC reader for mobile payments.
WLAN Security WPA3 -
Messaging Services SMS, MMS -
MEDIA Xiaomi MI 9 Samsung Galaxy S21 Ultra 5G
Supported Digital Audio Standards WAV, AAC, AMR, MP3, FLAC, apt-X, LDAC, apt-X HD WAV, WMA, AAC, PCM, AMR, MP3, FLAC, XMF, OGG, MIDI, APE (Monkey's Audio), M4A, DSF, DSD, MXMF, OGA, 3GA, AWB, IMY, RTTTL, RTX, OTA, DFF, MID, DSD64, DSD128
Supported Digital Video Standards MKV, VC-1, XviD, MPEG-4, H.264, M4V, HEVC, VP8, VP9 MKV, FLV, AVI, WMV, ASF, 3GP, M4V, WebM, 3G2, MP4
Sound Enhancements Qualcomm TrueWireless Stereo Plus Dolby Digital Plus sound, Dolby Atmos sound technology, Surround sound, stereo speakers tuned by AKG, Dolby Digital sound
FEATURES Xiaomi MI 9 Samsung Galaxy S21 Ultra 5G
Phone Functions Speakerphone, voice control, call timer, conference call, flight mode, voice dialing, vibrating alert Speakerphone, voice control, call timer, conference call, flight mode, voice dialing, vibrating alert
Sensors Accelerometer, ambient light sensor, digital compass, gyro sensor, ultrasonic proximity sensor, linear rotation vector sensor Accelerometer, ambient light sensor, proximity sensor, barometer, gyro sensor, hall sensor, geomagnetic sensor
Security Devices Fingerprint reader (under display) Fingerprint reader (under display), face recognition
Additional Phone Features Infrared remote control, MIMO technology, MU-MIMO technology, MI Turbo, GAME Turbo Air View, MIMO technology, Smart Select, Samsung KNOX, Smart View, Live message, Screen off memo, Bixby Vision, Dual Audio, Bixby Routines, Intelligent Performance Enhancer, AR Doodle, PENUP, Bixby key, Samsung Knox Vault, Private Share function, Enhanced Game Booster, Air Command
OTHERS Xiaomi MI 9 Samsung Galaxy S21 Ultra 5G
Included Accessories Protective cover, SIM card removal tool, USB-C cable, USB-C audio adapter, 18W QC3.0 charger SIM card removal tool, USB-C to USB-C cable
Compliant Standards TUV Rheinland Certified Safe Fast-Charge System IP68, HAC (Hearing Aid Compatible)
Max Depth of Water Resistance - 1.5 m
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