Xiaomi Redmi 9A vs. Samsung Galaxy S21 Ultra 5G

Phone Comparison, Reviews and Tests

Side by side comparison and review of Xiaomi Redmi 9A 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 Redmi 9A vs. Samsung Galaxy S21 Ultra 5G Comparison Chart
DESIGN AND DIMENSIONS Xiaomi Redmi 9A Samsung Galaxy S21 Ultra 5G
Product Type Smartphone Smartphone
Manufacturer Model Number - SM-G998B/DS
Form Factor Touch Touch
Height 164.9 mm 161.5 mm Xiaomi Redmi 9A has greater height than Samsung Galaxy S21 Ultra 5G.
Width 77.07 mm 75.6 mm Xiaomi Redmi 9A has greater width than Samsung Galaxy S21 Ultra 5G.
Depth 9 mm 8.9 mm Samsung Galaxy S21 Ultra 5G is narrower than Xiaomi Redmi 9A.
Weight 196 g 227 g Xiaomi Redmi 9A is lighter than Xiaomi Redmi 9A.
Body Colour Sky blue | Granite grey Phantom silver | Phantom black | Phantom navy | Phantom brown | Phantom titanium
Protection - Dustproof, splashproof, water-resistant
Waterproof (Water-resistant) - Yes Samsung Galaxy S21 Ultra 5G is waterproof.
IP rating - IP68
SAR Value 0.398 W/kg (head), 1.186 W/kg (body), 2.526 W/kg (limb) 1.58 W/kg (body), 0.714 W/kg (head), 2.56 W/kg (limb)
Integrated Components FM radio -
Connector Type Micro-USB - 5 pin Micro-USB Type B
Headset jack - mini-phone 3.5mm
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 Redmi 9A Samsung Galaxy S21 Ultra 5G
Display Type - OLED display
Display Technology - Infinity-O Dynamic AMOLED 2X
Screen Size (Display Size) 6.53" 6.8" Samsung Galaxy S21 Ultra 5G has larger screen size than Xiaomi Redmi 9A.
Screen Resolution (Display Resolution) 1600 x 720 pixels 3200 x 1440 pixels Samsung Galaxy S21 Ultra 5G has better screen resolution than Xiaomi Redmi 9A.
Display Format HD+ QHD+
Pixel Density - 515 ppi
Aspect Ratio 20:9 -
Max Brightness 400 cd/m² -
Colour Depth - 16.7 million colours
Contrast Ratio 1500:1 -
HDR - Yes Samsung Galaxy S21 Ultra 5G has HDR.
HDR Technology - HDR10+
Display Enhancement Technology Blue light filter, Sunlight mode Eye Comfort Shield
Display Refresh Rate - 120 Hz
Display Features Reading mode, Colour temperature adjustment, Dot Drop display Edge Screen, AOD(Always On Display)
Display Protection (Screen Protector) - Corning Gorilla Glass Victus (scratch resistant glass)
PROCESSOR Xiaomi Redmi 9A Samsung Galaxy S21 Ultra 5G
Processor Type (CPU) MediaTek Helio G25 Samsung Exynos 2100
Clock Speed 2 GHz 2.9 GHz Samsung Galaxy S21 Ultra 5G has higher clock speed than Xiaomi Redmi 9A.
Processor Core Qty 8-core 8-core Both phones have the same number of phone cores.
64-bit Architecture Yes - Xiaomi Redmi 9A has 64-bit architecture.
Graphics System (GPU) PowerVR GE8320 Mali-G78 MP14
MEMORY Xiaomi Redmi 9A Samsung Galaxy S21 Ultra 5G
RAM LPDDR4X SDRAM - 2 GB LPDDR5 SDRAM - 12 GB Samsung Galaxy S21 Ultra 5G has more RAM than Xiaomi Redmi 9A.
Internal Memory Size (Storage Capacity) 32 GB 128 GB Samsung Galaxy S21 Ultra 5G has more internal memory than Xiaomi Redmi 9A.
User Memory - 101.7 GB
Supported Flash Memory Cards (Expandable Memory) microSD -
CAMERA Xiaomi Redmi 9A Samsung Galaxy S21 Ultra 5G
MAIN CAMERA
Number of Main Cameras 1 4
Sensor Resolution 13 Megapixel 12 Megapixel Xiaomi Redmi 9A has better camera resolution than Samsung Galaxy S21 Ultra 5G.
Lens Type - Ultra wide-angle lens
Lens Aperture - F/2.2
Field of View (FoV) - 120 degree(s)
Pixel Size - 1.4 μm
Optical Image Stabiliser (OIS) - Optical Image Stabiliser (OIS) Samsung Galaxy S21 Ultra 5G has optical stabilisation.
Focus Adjustment Automatic Automatic
Laser Auto Focus - Yes
Optical Zoom - 3x
Digital Zoom - 100x
Self-Timer Delay - Yes
Special Effects HDR, Kaleidoscope Face retouch, Grid Line
HDR Mode - Auto HDR mode
Camera Modes AI portrait mode, AI Beautify 5.0 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 Redmi 9A has face detection.
Light Source Single tone LED flash High CRI LED flash
Video Resolutions 1920 x 1080 (1080p) at 30 fps, 1920 x 1080 (1080p) at 60 fps, 1280 x 720 (720p) at 30 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) Phase Detect Auto-Focus (PDAF), AI scene detection 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) - 108 Megapixel
Sensor Size (2nd Camera) - 1/1.33"
Lens Type (2nd Camera) - Wide-angle lens
Lens Aperture (2nd Camera) - F/1.8
Field of View (2nd Camera) - 83 degree(s)
Pixel Size (2nd Camera) - 0.8 μm
Camera Features (2nd Camera) - Phase Detect Auto-Focus (PDAF), OIS (Optical Image Stabilisation)
THIRD CAMERA
Sensor Resolution (3rd Camera) - 10 Megapixel
Lens Type (3rd Camera) - Telephoto lens
Lens Aperture (3rd Camera) - F/2.4
Field of View (3rd Camera) - 35 degree(s)
Pixel Size (3rd Camera) - 1.22 μm
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) 5 Megapixel 40 Megapixels Samsung Galaxy S21 Ultra 5G has better front camera resolution than Xiaomi Redmi 9A.
Lens Aperture (Front) F/2.2 F/2.2 Both phones have the same front camera lens aperture.
Field of View (Front) - 80 degree(s)
Pixel Size (Front) 1.12 μm 0.7 μm Xiaomi Redmi 9A has larger front camera pixel size than Samsung Galaxy S21 Ultra 5G.
Focus Adjustment - Automatic
Special Effects (Front) HDR -
Camera Modes (Front) AI portrait mode, Portrait, AI Beautify 5.0 -
Face Recognition (Face ID) Face recognition - Xiaomi Redmi 9A has face detection.
Light Source (Front) Display flash -
Camera Features (Front) Self-timer, Palm shutter Phase Detect Auto-Focus (PDAF)
BATTERY AND CHARGING Xiaomi Redmi 9A Samsung Galaxy S21 Ultra 5G
Battery Capacity (Battery Size) 5000 mAh 5000 mAh Both phones have the same battery capacity.
Fast Charging Technology - Qualcomm Quick Charge 2.0, Adaptive Fast Charging, Samsung Super Fast Charging, Power Delivery 3.0 Samsung Galaxy S21 Ultra 5G has fast charging technology.
Wireless Charging - Yes Samsung Galaxy S21 Ultra 5G can be charged wirelessly.
Wireless Charging Standards - WPC, Qi, Fast Wireless Charging 2.0, Wireless PowerShare
Standby Time 816 hours -
Talk Time 2280 minutes 2460 minutes Samsung Galaxy S21 Ultra 5G has longer battery life when making calls than Xiaomi Redmi 9A.
Run Time Details Standby: up to 816 hrs
Playback (audio): up to 168 hrs
Talk: up to 2280 min
Playback (video): up to 19 hrs
Gaming: up to 14 hrs
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 Redmi 9A Samsung Galaxy S21 Ultra 5G
Technology WCDMA (UMTS) / GSM WCDMA (UMTS) / GSM
Mobile Broadband Generation 4G 5G Samsung Galaxy S21 Ultra 5G has more advanced generation mobile network.
Operating System - Android 11
Intelligent Assistant - Bixby
Payment Technology - Samsung Pay
Navigation GPS, A-GPS, GLONASS, BeiDou GPS, GLONASS, BeiDou, Galileo
COMMUNICATIONS Xiaomi Redmi 9A Samsung Galaxy S21 Ultra 5G
Data Transmission FDD-LTE, TDD-LTE FDD-LTE, TDD-LTE, 5G NR FR1
2G Band 850 GSM, 900 GSM, 1800 GSM, 1900 GSM 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 20, Band 28, Band 38, Band 40, Band 41 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 800 DD, FDD 700 APT, TDD 2600, TDD 2300, TDD 2500 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 802.11b/g/n IEEE 802.11a/b/g/n/ac/ax
Bluetooth Bluetooth 5.0 Bluetooth 5.2
NFC - Yes Samsung Galaxy S21 Ultra 5G has NFC reader for mobile payments.
Messaging Services SMS, MMS -
MEDIA Xiaomi Redmi 9A Samsung Galaxy S21 Ultra 5G
Supported Digital Audio Standards AAC, PCM, MP3, FLAC, AAC +, eAAC+, APE (Monkey's Audio), AMR-WB, AMR-NB 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, MPEG4-ASP, MPEG-4 SP, H.264 BP, H.264 MP, H.264 HP MKV, FLV, AVI, WMV, ASF, 3GP, M4V, WebM, 3G2, MP4
Sound Enhancements 0.64cc Sound Chamber Dolby Digital Plus sound, Dolby Atmos sound technology, Surround sound, stereo speakers tuned by AKG, Dolby Digital sound
FEATURES Xiaomi Redmi 9A 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, distance sensor Accelerometer, ambient light sensor, proximity sensor, barometer, gyro sensor, hall sensor, geomagnetic sensor
Security Devices Face recognition Fingerprint reader (under display), face recognition
Additional Phone Features AI face unlock, HyperEngine technology 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 Redmi 9A Samsung Galaxy S21 Ultra 5G
Included Accessories USB cable, SIM card removal tool, 10W charger SIM card removal tool, USB-C to USB-C cable
Compliant Standards - IP68, HAC (Hearing Aid Compatible)
Max Depth of Water Resistance - 1.5 m
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