Realme C21 vs vivo X100

Network
2G network

GSM 850, 900, 1800, 1900

GSM 850, 900, 1800, 1900; CDMA 800
3G network

HSDPA 850, 900, 2100

HSDPA 800, 850, 900, 1700(AWS), 1900, 2100
4G network

LTE frequency band 1, 3, 5, 7, 8, 20, 28, 38, 40, 41

LTE frequency band 1, 2, 3, 4, 5, 7, 8, 18, 19, 26, 28, 34, 38, 39, 40, 41
5G network

-

5G band 1, 3, 5, 8, 28, 38, 40, 41, 77, 78 SA/NSA
HSDPA speed

42.2 Mbps

42.2 Mbps
HSUPA speed

5.76 Mbps

5.76 Mbps
EV-DO speed

-

EV-DO Rev.A 3.1 Mbps download, 1.8 Mbps upload
LTE speed

LTE, Cat4, 150 Mbps download, 51 Mbps upload

LTE-A
GPRS

Yes

Yes
EDGE

Yes

Yes

Design
Build

Glass front, plastic back, plastic frame

Aluminium alloy, glass, faux leather
SIM

Dual SIM (Nano-SIM, dual stand-by)

Dual SIM (Nano-SIM, dual stand-by)
Height

165.2 mm

164.1 mm
Width

76.4 mm

75.2 mm
Thickness

8.9 mm

8.5/8.8 mm
Weight

190 g

202/206 g
Waterproof

-

IP68 (1.5m and 30 mins)
Dust proof

-

IP68
Colors

Black, Blue

Black, Blue, Orange

Display
Display type

IPS LCD

LTPO AMOLED
Physical size

6.5 inches

6.78 inches
Resolution

720 x 1600 pixels

1260 x 2800 pixels
Pixel density

270 ppi

453 ppi
Display colors

16777216

1073741824
Protection

Scratch resistant, 2.5D curved glass screen, Corning Gorilla Glass 3

Scratch resistant

OS
OS

Android 10, Realme UI 1.0 / Android 11, Realme UI 2.0

Android 14, Funtouch 14 (global), OriginOS 4 (China)

Main camera
Camera type

Triple

Triple
Main camera

(wide) , 13 MP, f/2.2 , 26 mm, 1/3.06" , 1.12 µm

(wide) , 50 MP, f/1.6 , 1/1.49"
(macro) , 2 MP, f/2.4

(periscope telephoto) , 64 MP, f/2.6 , 70 mm, 1/2.0" , 3x optical zoom
(depth) , 2 MP, f/2.4

(ultrawide) , 50 MP, f/2.0 , 119˚ , 15 mm, 1/2.76"
Primary camera resolution

2560 x 1920 pixels

8120 x 6180 pixels
Primary camera video

1080p@30fps

4K, 1080p, gyro-EIS, Cinematic mode (1080p)
Primary camera optics

-

Zeiss optics, Zeiss T* lens coating
Primary camera flash

LED flash

LED flash
Camera features

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

Autofocus, continuous shooting, digital zoom, optical 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

Connectivity
WLAN

Wi-Fi 802.11b, 802.11g, 802.11n

Wi-Fi 802.11a, 802.11b, 802.11g, 802.11n, 802.11n 5GHz, 802.11ac, 802.11ax, 802.11be
WLAN WiFi Hotspot

Yes

-
WLAN WiFi Direct

-

Yes
WiFi Tri-Band

-

Yes
USB

microUSB 2.0

Type-C 2.0
USB On-The-Go

Yes

Yes
Bluetooth

v5.0

v5.4
Bluetooth A2DP

Yes

Yes
bluetooth LE

Yes

Yes
Bluetooth AptX

-

aptX HD
Infrared

-

Yes
NFC

No

Yes
GPS

Yes, with A-GPS

Yes, with A-GPS
GLONASS

Yes

Yes
GALILEO

-

Yes
BDS

Yes

Yes
QZSS

-

Yes
NavIC

-

Yes