Xiaomi MI 9 vs. Realme C21

Phone Comparison, Reviews and Tests

In depth comparison and review of Xiaomi MI 9 and Realme C21. Compare sizes, cameras, batteries, memory, and other important specifications and features to easily choose the right phone for you. Our goal is to help you uncover differences between the products and find the phone that will best fit your needs.

Phone Specifications Comparison

Xiaomi MI 9 vs. Realme C21 Comparison Chart
DESIGN AND DIMENSIONS Xiaomi MI 9 Realme C21
Product Type Smartphone Smartphone
Form Factor Touch Touch
Height 157.5 mm 165.2 mm Realme C21 has greater height than Xiaomi MI 9.
Width 74.67 mm 76.4 mm Realme C21 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 190 g Xiaomi MI 9 is lighter than Xiaomi MI 9.
Body Colour Ocean blue | Piano black Cross black | Cross blue
Body Material Curved glass -
Waterproof (Water-resistant) - -
SAR Value 1.301 W/kg (body), 1.389 W/kg (head) -
Connector Type USB Type-C - 24 pin USB-C Micro-USB
Headset jack - mini-phone 3.5mm
SIM Card Type (Size) Nano SIM Nano SIM
SIM Card Qty Dual-SIM Dual-SIM
DISPLAY Xiaomi MI 9 Realme C21
Display Type OLED display LCD display
Display Technology AMOLED LCD
Screen Size (Display Size) 6.39" 6.5" Realme C21 has larger screen size than Xiaomi MI 9.
Screen Resolution (Display Resolution) 2340 x 1080 pixels 1600 x 720 pixels Xiaomi MI 9 has better screen resolution than Realme C21.
Display Format Full HD+ HD+
Pixel Density 403 ppi -
Aspect Ratio - 20:9
Max Brightness 600 cd/m² 420 cd/m² Xiaomi MI 9 has better display brightness than Realme C21.
Contrast Ratio 60000:1 -
HDR Yes - Xiaomi MI 9 has HDR.
HDR Technology HDR10 -
Display Enhancement Technology Sunshine mode 2.0 -
Display Features Always-on display, Reading mode, Colour temperature adjustment, night mode, Wide Colour Gamut (WCG) Mini-drop display
Display Protection (Screen Protector) Fingerprint-resistant coating, Corning Gorilla Glass 6 (scratch resistant glass), oil protective coating -
PROCESSOR Xiaomi MI 9 Realme C21
Processor Type (CPU) Qualcomm Snapdragon 855 MediaTek Helio G35
Clock Speed 2.84 GHz 2.3 GHz Xiaomi MI 9 has higher clock speed than Realme C21.
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 PowerVR GE8320
MEMORY Xiaomi MI 9 Realme C21
RAM LPDDR4X SDRAM - 6 GB LPDDR4X SDRAM - 3 GB Xiaomi MI 9 has more RAM than Realme C21.
Internal Memory Size (Storage Capacity) 64 GB 32 GB Xiaomi MI 9 has more internal memory than Realme C21.
Supported Flash Memory Cards (Expandable Memory) - microSD
CAMERA Xiaomi MI 9 Realme C21
MAIN CAMERA
Number of Main Cameras 3 3
Sensor Resolution 48 Megapixel 13 Megapixel Xiaomi MI 9 has better camera resolution than Realme C21.
Sensor Name Sony Exmor RS IMX586 sensor -
Lens Type Ultra wide-angle lens -
Lens Aperture F/1.75 F/2.2 Xiaomi MI 9 has better lens aperture than Xiaomi MI 9.
Lens Construction - 5-element
Pixel Size 0.8 μm -
Focus Adjustment Automatic Automatic
Laser Auto Focus Yes -
Optical Zoom 2x -
Digital Zoom 10x 4x Xiaomi MI 9 has better digital zoom than Realme C21.
Special Effects HDR HDR
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, Time-lapse mode, Slow motion mode, Beauty mode, Expert Mode, Nightscape capture mode, Portrait, Filter mode, Super nightscape
Face Recognition (Face ID) Face recognition - Xiaomi MI 9 has face detection.
Light Source Dual flash 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 30 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 Phase Detect Auto-Focus (PDAF), AI Triple camera, Chroma boost
SECOND CAMERA
Sensor Resolution (2nd Camera) 12 Megapixel 2 Megapixel Xiaomi MI 9 has better second camera resolution than Realme C21.
Lens Type (2nd Camera) Telephoto lens -
Lens Aperture (2nd Camera) F/2.2 F/2.4 Xiaomi MI 9 has better second camera lens aperture than Xiaomi MI 9.
Lens Element Qty (2nd Camera) - 3-element
Pixel Size (2nd Camera) 1 μm -
Camera Functions (2nd Camera) - B&W lens
Camera Features (2nd Camera) Macro photography -
THIRD CAMERA
Sensor Resolution (3rd Camera) 16 Megapixel 2 Megapixel Xiaomi MI 9 has higher resolution third camera than Realme C21.
Lens Type (3rd Camera) Ultra wide-angle lens -
Lens Aperture (3rd Camera) F/2.2 F/2.4 Xiaomi MI 9 has better third camera lens aperture than Xiaomi MI 9.
Lens Element Qty (3rd Camera) - 3-element
Pixel Size (3rd Camera) 1 μm -
Camera Functions (3rd Camera) - Macro camera
Camera Features (3rd Camera) - 4cm macro photography
FRONT CAMERA
Number of Front Cameras 1 1
Sensor Resolution (Front) 20 Megapixel 5 Megapixel Xiaomi MI 9 has better front camera resolution than Realme C21.
Lens Aperture (Front) F/2.0 F/2.2 Xiaomi MI 9 has better front lens aperture than Xiaomi MI 9.
Lens Element Qty (Front) - 3-element
Pixel Size (Front) 0.9 μm -
Special Effects (Front) HDR, Magic mirror HDR
Camera Modes (Front) AI portrait mode, AI Beautify, AI makeup Time-lapse mode, Beauty mode, portrait mode, AI Beauty, Filter mode, Panoramic mode
Face Recognition (Face ID) Face recognition Face recognition Both phones have 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 -
BATTERY AND CHARGING Xiaomi MI 9 Realme C21
Battery Capacity (Battery Size) 3300 mAh 5000 mAh Realme C21 has larger battery capacity than Xiaomi MI 9.
Fast Charging Technology Qualcomm Quick Charge 4.0+ - Xiaomi MI 9 has fast charging technology.
Wireless Charging Standards WPC, Qi -
CELLULAR Xiaomi MI 9 Realme C21
Technology CDMA2000 1X / GSM / WCDMA (UMTS) / TD-SCDMA WCDMA (UMTS) / GSM
Mobile Broadband Generation 4G 4G Both phones have the same mobile network generation.
Operating System - Android 10
User Interface MIUI 10 Realme UI
Intelligent Assistant Google Assistant -
Payment Technology Android Pay -
Navigation GPS, A-GPS, GLONASS, BeiDou, Galileo GPS, A-GPS, GLONASS, BeiDou
COMMUNICATIONS Xiaomi MI 9 Realme C21
Data Transmission GPRS, EDGE, EV-DO, HSDPA, HSUPA, HSPA+, VoLTE, FDD-LTE, TDD-LTE FDD-LTE, TDD-LTE
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 5, Band 8
3G UMTS Frequency 2100, 1900, 1700, 850, 900 2100, 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 3, Band 5, Band 7, Band 8, Band 20, Band 28, Band 38, Band 40, Band 41
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 1800+, FDD 850, FDD 2600, FDD 900, FDD 800 DD, FDD 700 APT, TDD 2600, TDD 2300, TDD 2500
Wireless Interface IEEE 802.11a/b/g/n/ac IEEE 802.11b/g/n
Bluetooth Bluetooth 5.0 Bluetooth 5.0
NFC Yes - Xiaomi MI 9 has NFC reader for mobile payments.
WLAN Security WPA3 -
Messaging Services SMS, MMS -
MEDIA Xiaomi MI 9 Realme C21
Supported Digital Audio Standards WAV, AAC, AMR, MP3, FLAC, apt-X, LDAC, apt-X HD -
Supported Digital Video Standards MKV, VC-1, XviD, MPEG-4, H.264, M4V, HEVC, VP8, VP9 -
Sound Enhancements Qualcomm TrueWireless Stereo Plus -
FEATURES Xiaomi MI 9 Realme C21
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, proximity sensor, magnetometer, light sensor
Security Devices Fingerprint reader (under display) Fingerprint reader
Additional Phone Features Infrared remote control, MIMO technology, MU-MIMO technology, MI Turbo, GAME Turbo Super power saving mode, HyperEngine technology, Reverse charging
OTHERS Xiaomi MI 9 Realme C21
Included Accessories Protective cover, SIM card removal tool, USB-C cable, USB-C audio adapter, 18W QC3.0 charger USB cable, power adapter, SIM card removal tool
Compliant Standards TUV Rheinland Certified Safe Fast-Charge System TUV Rheinland
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