Oppo K9 vs Realme C51

Network
2G network

GSM 850, 900, 1800, 1900; CDMA 800

GSM 850, 900, 1800, 1900
3G network

HSDPA 800, 850, 900, 1700(AWS), 1900, 2100; CDMA2000 1x

HSDPA 850, 900, 2100
4G network

LTE frequency band 1, 3, 4, 5, 8, 28, 34, 38, 39, 40, 41

LTE frequency band 1, 3, 5, 8, 38, 40, 41 - Africa, India; 1, 3, 5, 7, 8, 20, 28, 38, 40, 41 - Asia
5G network

5G band 1, 3, 28, 41, 77, 78 SA/NSA

-
HSDPA speed

42.2 Mbps

42.2 Mbps
HSUPA speed

5.76 Mbps

5.76 Mbps
LTE speed

LTE-A, 1200 Mbps download, 210 Mbps upload

LTE-A, 150 Mbps download, 51 Mbps upload
GPRS

Yes

Yes
EDGE

Yes

Yes

Display
Display type

Super AMOLED

IPS LCD
Physical size

6.43 inches

6.74 inches
Resolution

1080 x 2400 pixels

720 x 1600 pixels
Pixel density

409 ppi

260 ppi
Display colors

16777216

16777216
Protection

Scratch resistant, 2.5D curved glass screen

Scratch resistant, 2.5D curved glass screen
Display features

90Hz, 430 nits (typ), 750 nits (peak)

90Hz, 560 nits (peak)

Main camera
Camera type

Triple

Dual
Main camera

(wide) , 64 MP, f/1.7 , 80˚ , 1/2.0" , 0.8 µm, 20x digital zoom

(wide) , 50 MP, f/1.8 , 1/2.76" , 0.64 µm, 27 mm
(ultrawide) , 8 MP, f/2.2 , 119˚

(depth) , 0.08 MP, f/3.0
(macro) , 2 MP, f/2.4
Primary camera resolution

9280 x 6920 pixels

8120 x 6180 pixels
Primary camera video

4K@30fps, 1080p@30/60/120fps; gyro-EIS

1080p@30fps
Primary camera flash

LED flash

LED flash
Camera features

Autofocus, continuous autofocus, continuous shooting, digital zoom, digital image stabilization, optical image stabilization, geotagging, panorama, HDR, touch focus, face detection, white balance settings, ISO settings, exposure compensation, self-timer, scene-mode, macro-mode, phase detection autofocus, contrast detection autofocus

Autofocus, digital zoom, digital image stabilization, geotagging, panorama, HDR, touch focus, face detection, white balance settings, ISO settings, exposure compensation, self-timer, scene-mode, phase detection autofocus

Selfie camera
Selfie camera type

Single

Single
Selfie camera

(wide) , 32 MP, f/2.4 , 80˚ , 0.8 µm

(wide) , 5 MP, f/1.8 , 1.12 µm, 28 mm, 1/5"
Selfie camera resolution

6560 x 4928 pixels

3264 x 2448 pixels
Selfie camera features

Face unlock, digital image stabilization

Face unlock, face detection
Selfie camera video

1080p@30fps

720p@30fps

Connectivity
WLAN

Wi-Fi 802.11a, 802.11b, 802.11g, 802.11n, 802.11n 5Ghz, 802.11ac

Wi-Fi 802.11a, 802.11b, 802.11g, 802.11n, 802.11n 5Ghz, 802.11ac
WLAN WiFi Hotspot

Yes

-
WLAN WiFi Direct

Yes

-
WLAN WiFi Dual Band

Yes

Yes
USB

Type-C 2.0

Type-C 2.0
USB On-The-Go

Yes

-
Bluetooth

v5.0

v5.0
Bluetooth A2DP

Yes

Yes
bluetooth LE

Yes

Yes
Bluetooth AptX

aptX HD

-
NFC

No

Yes
GPS

Yes, with A-GPS

Yes, with A-GPS
GLONASS

Yes

Yes
GALILEO

Yes

Yes
BDS

Yes

-
QZSS

Yes

-

Features
Sensors

Accelerometer, compass, fingerprint, gyroscope, proximity

Accelerometer, compass, fingerprint, proximity

Battery
Battery type

Li-Po

Li-Po
Battery capacity

4300 mAh

5000 mAh
Battery removable

Non-removable

Non-removable
Fast battery charging

VOOC 4.0 (100% in 35 min)

SuperVOOC, 33W (50% in 28 min)