ASUS ZenFone 3 (ZE520KL) vs. Realme C21

Phone Comparison, Reviews and Tests

In depth comparison and review of ASUS ZenFone 3 (ZE520KL) 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

ASUS ZenFone 3 (ZE520KL) vs. Realme C21 Comparison Chart
DESIGN AND DIMENSIONS ASUS ZenFone 3 (ZE520KL) Realme C21
Product Type Smartphone Smartphone
Manufacturer Model Number ZE520KL -
Form Factor Touch Touch
Height 146.87 mm 165.2 mm Realme C21 has greater height than ASUS ZenFone 3 (ZE520KL).
Width 73.98 mm 76.4 mm Realme C21 has greater width than ASUS ZenFone 3 (ZE520KL).
Depth 7.69 mm 8.9 mm ASUS ZenFone 3 (ZE520KL) is narrower than ASUS ZenFone 3 (ZE520KL).
Weight 144 g 190 g ASUS ZenFone 3 (ZE520KL) is lighter than ASUS ZenFone 3 (ZE520KL).
Body Colour Moon white | Gold shimmer | Black sapphire Cross black | Cross blue
Body Material Metal, glass -
Waterproof (Water-resistant) - -
SAR Value 0.938 W/kg (body), 0.278 W/kg (head) -
Integrated Components FM radio -
Connector Type Headset jack - mini-phone 3.5mm
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 (SIM1 and SIM2/MicroSD slots) Dual-SIM
SIM Card Configuration Details Nano SIM + nano SIM/microSD -
DISPLAY ASUS ZenFone 3 (ZE520KL) Realme C21
Display Type LCD display LCD display
Display Technology Super IPS+ LCD
Screen Size (Display Size) 5.2" 6.5" Realme C21 has larger screen size than ASUS ZenFone 3 (ZE520KL).
Screen Resolution (Display Resolution) 1920 x 1080 pixels 1600 x 720 pixels ASUS ZenFone 3 (ZE520KL) has better screen resolution than Realme C21.
Display Format Full HD HD+
Aspect Ratio - 20:9
Max Brightness 600 cd/m² 420 cd/m² ASUS ZenFone 3 (ZE520KL) has better display brightness than Realme C21.
Display Enhancement Technology Bluelight Filter for Eye Care -
Display Features ASUS Glove Touch technology, 2.5D curved glass Mini-drop display
Display Protection (Screen Protector) Fingerprint-resistant oleophobic coating, Corning Gorilla Glass (scratch resistant glass) -
PROCESSOR ASUS ZenFone 3 (ZE520KL) Realme C21
Processor Type (CPU) Qualcomm Snapdragon 625 MediaTek Helio G35
Clock Speed 2 GHz 2.3 GHz Realme C21 has higher clock speed than ASUS ZenFone 3 (ZE520KL).
Processor Core Qty 8-core 8-core Both phones have the same number of phone cores.
64-bit Architecture Yes - ASUS ZenFone 3 (ZE520KL) has 64-bit architecture.
Graphics System (GPU) Qualcomm ADRENO 506 PowerVR GE8320
MEMORY ASUS ZenFone 3 (ZE520KL) Realme C21
RAM 3 GB LPDDR4X SDRAM - 3 GB Both phones have the same RAM size.
Internal Memory Size (Storage Capacity) 32 GB 32 GB Both phones have the same internal memory capacity.
Supported Flash Memory Cards (Expandable Memory) microSDHC, microSDXC - up to 2 TB microSD
CAMERA ASUS ZenFone 3 (ZE520KL) Realme C21
MAIN CAMERA
Number of Main Cameras 1 3
Sensor Resolution 16 Megapixel 13 Megapixel ASUS ZenFone 3 (ZE520KL) has better camera resolution than Realme C21.
Sensor Name Sony Exmor RS IMX298 sensor -
Lens Aperture F/2.0 F/2.2 ASUS ZenFone 3 (ZE520KL) has better lens aperture than ASUS ZenFone 3 (ZE520KL).
Lens Construction 6-element 5-element
Optical Image Stabiliser (OIS) 4 Stop OIS (Optical Image Stabilisation) - ASUS ZenFone 3 (ZE520KL) has optical stabilisation.
Focus Adjustment Automatic Automatic
Laser Auto Focus Yes -
Digital Zoom - 4x
Special Effects Depth of field HDR
HDR Mode Auto HDR mode -
Camera Modes Panorama, Time-lapse mode, night mode, manual mode, Real time beauty mode, super resolution mode, All Smiles mode, Mini mode Panorama, Time-lapse mode, Slow motion mode, Beauty mode, Expert Mode, Nightscape capture mode, Portrait, Filter mode, Super nightscape
Light Source Dual LED flash LED flash
Video Resolutions 3840 x 2160 (4K) 1920 x 1080 (1080p) at 30 fps
Camera Features (Functions) Sapphire crystal lens cover, GIF animation function, Smart Remove, Electronic Image Stabiliser (EIS), Time Rewind, Largan lens Phase Detect Auto-Focus (PDAF), AI Triple camera, Chroma boost
SECOND CAMERA
Sensor Resolution (2nd Camera) - 2 Megapixel
Lens Aperture (2nd Camera) - F/2.4
Lens Element Qty (2nd Camera) - 3-element
Camera Functions (2nd Camera) - B&W lens
THIRD CAMERA
Sensor Resolution (3rd Camera) - 2 Megapixel
Lens Aperture (3rd Camera) - F/2.4
Lens Element Qty (3rd Camera) - 3-element
Camera Functions (3rd Camera) - Macro camera
Camera Features (3rd Camera) - 4cm macro photography
FRONT CAMERA
Number of Front Cameras 1 1
Sensor Resolution (Front) 8 Megapixel 5 Megapixel ASUS ZenFone 3 (ZE520KL) has better front camera resolution than Realme C21.
Lens Aperture (Front) F/2.0 F/2.2 ASUS ZenFone 3 (ZE520KL) has better front lens aperture than ASUS ZenFone 3 (ZE520KL).
Lens Element Qty (Front) - 3-element
Special Effects (Front) - HDR
HDR Mode (Front) Auto HDR mode -
Camera Modes (Front) Selfie panorama Time-lapse mode, Beauty mode, portrait mode, AI Beauty, Filter mode, Panoramic mode
Face Recognition (Face ID) - Face recognition Realme C21 has face detection.
Camera Features (Front) PixelMaster camera -
BATTERY AND CHARGING ASUS ZenFone 3 (ZE520KL) Realme C21
Battery Capacity (Battery Size) 2650 mAh 5000 mAh Realme C21 has larger battery capacity than ASUS ZenFone 3 (ZE520KL).
CELLULAR ASUS ZenFone 3 (ZE520KL) Realme C21
Technology WCDMA (UMTS) / GSM WCDMA (UMTS) / GSM
Mobile Broadband Generation 4G 4G Both phones have the same mobile network generation.
Operating System Android 6.0 (Marshmallow) Android 10
User Interface ASUS ZenUI 3.0 Realme UI
Navigation GPS, A-GPS, GLONASS, BeiDou GPS, A-GPS, GLONASS, BeiDou
COMMUNICATIONS ASUS ZenFone 3 (ZE520KL) Realme C21
Data Transmission GPRS, EDGE, HSDPA, HSUPA, HSPA+, LTE, FDD-LTE, DC-HSPA+ FDD-LTE, TDD-LTE
2G Band 850 GSM, 900 GSM, 1800 GSM, 1900 GSM 850 GSM, 900 GSM, 1800 GSM, 1900 GSM
3G UMTS Band - Band 1, Band 5, Band 8
3G UMTS Frequency - 2100, 850, 900
4G LTE Band Band 1, Band 2, Band 3, Band 5, Band 7, Band 8, Band 20 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 850, FDD 2600, FDD 900, FDD 800 DD FDD 2100, FDD 1800+, FDD 850, FDD 2600, FDD 900, FDD 800 DD, FDD 700 APT, TDD 2600, TDD 2300, TDD 2500
Wireless Interface Infrared (IrDA), IEEE 802.11b/g/n/ac IEEE 802.11b/g/n
Bluetooth Bluetooth 4.2 Bluetooth 5.0
Messaging Services SMS, MMS -
FEATURES ASUS ZenFone 3 (ZE520KL) 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, proximity sensor, digital compass, gyro sensor, hall sensor, RGB sensor Accelerometer, proximity sensor, magnetometer, light sensor
Security Devices Fingerprint reader Fingerprint reader
Additional Phone Features Infrared remote control, Dual microphones, Hi-Res Audio, Google Drive Storage (100 GB) (free for 2 years), ASUS SonicMaster 3.0 technology, ASUS NoiseZero Talk technology Super power saving mode, HyperEngine technology, Reverse charging
OTHERS ASUS ZenFone 3 (ZE520KL) Realme C21
Included Accessories Power adapter USB cable, power adapter, SIM card removal tool
Compliant Standards - TUV Rheinland
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