Screen size
A4+Winner: 4.0"+30%
KT21 Express2.8"
Quick verdict
A4+ leads the measured specs 7-1.
Measured wins
A4+
7
spec wins
Overall winner
Ties
5
equal specs
KT21 Express
1
spec wins
Screen size
Technology
A4+
GSM
KT21 Express
No cellular connectivity
2G bands
A4+
GSM 900 / 1800 / 1900 - SIM 1 & SIM 2
KT21 Express
GSM - SIM 1 & SIM 2
GPRS
A4+
Yes
KT21 Express
Yes
EDGE
A4+
Yes
KT21 Express
Resolution
Refresh rate
Peak brightness
Pixel density
CPU speed
RAM
Storage
Main camera
equal specsFront camera
Battery
Wired charging
Weight
Thickness
IP rating
Wi‑Fi
Bluetooth
USB
5G support
equal specsNFC
equal specs3.5mm jack
equal specsSD card
equal specsStereo speakers
Yes
Announced
A4+
2013. Released 2013
KT21 Express
2012
Status
A4+
Discontinued
KT21 Express
Discontinued
Dimensions
A4+
123 x 63 x 10.5 mm (4.84 x 2.48 x 0.41 in)
KT21 Express
-
Weight
A4+
87.5 g without battery (3.07 oz)
KT21 Express
-
SIM
A4+
Dual SIM
KT21 Express
Dual SIM (Mini-SIM)
Type
A4+
IPS LCD
KT21 Express
TFT
Size
A4+
4.0 inches, 45.5 cm2 (~58.8% screen-to-body ratio)
KT21 Express
2.8 inches, 24.3 cm2
Resolution
A4+
480 x 800 pixels, 5:3 ratio (~233 ppi density)
KT21 Express
240 x 320 pixels, 4:3 ratio
OS
A4+
Android 4.0 (Ice Cream Sandwich)
KT21 Express
-
CPU
A4+
Dual-core 1.0 GHz
KT21 Express
-
Card slot
A4+
microSDHC (dedicated slot)
KT21 Express
microSDHC (dedicated slot)
Internal
A4+
90MB
KT21 Express
-
Phonebook
A4+
-
KT21 Express
2000 entries
Call records
A4+
-
KT21 Express
Yes
Single
A4+
3.15 MP
KT21 Express
3.15 MP
Video
A4+
Yes
KT21 Express
Yes
Features
A4+
-
KT21 Express
LED flash
Other
A4+
No
KT21 Express
No
Loudspeaker
A4+
Yes
KT21 Express
Yes
3.5mm jack
A4+
Yes
KT21 Express
Yes
WLAN
A4+
Wi-Fi 802.11 b/g/n
KT21 Express
No
Bluetooth
A4+
Yes
KT21 Express
2.0
Positioning
A4+
No
KT21 Express
No
NFC
A4+
No
KT21 Express
No
Radio
A4+
FM radio
KT21 Express
FM radio, recording
USB
A4+
Proprietary
KT21 Express
microUSB
Sensors
A4+
Accelerometer, proximity
KT21 Express
Proximity
Messaging
A4+
-
KT21 Express
SMS, MMS, Email
Games
A4+
-
KT21 Express
Yes
Java
A4+
-
KT21 Express
Yes
Other
A4+
-
KT21 Express
Audio/video player Photo viewer Organizer
Type
A4+
Li-Ion 1250 mAh battery
KT21 Express
Li-Ion 1000 mAh, removable
Stand-by
A4+
Up to 125 h
KT21 Express
-
Talk time
A4+
Up to 5 h
KT21 Express
-
Colors
A4+
White/Black
KT21 Express
Black
SAR EU
A4+
0.94 W/kg (head)
KT21 Express
-
Price
A4+
About 50 EUR
KT21 Express
About 40 EUR