Screen size
A4Winner: 4.0"+30%
KT21 Express2.8"
Quick verdict
A4 leads the measured specs 6-1.
Measured wins
A4
6
spec wins
Overall winner
Ties
5
equal specs
KT21 Express
1
spec wins
Screen size
Technology
A4
GSM / HSPA
KT21 Express
No cellular connectivity
2G bands
A4
GSM 850 / 1900 - SIM 1 & SIM 2, GSM 900 / 1800 - SIM 1 & SIM 2
KT21 Express
GSM - SIM 1 & SIM 2
3G bands
A4
HSDPA 900 / 2100 , HSDPA 850 / 1900
KT21 Express
-
Speed
A4
HSPA
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
KT21 Express
-
GPRS
A4
-
KT21 Express
Yes
EDGE
A4
-
KT21 Express
Yes
Announced
A4
2013, March. Released 2013, March
KT21 Express
2012
Status
A4
Discontinued
KT21 Express
Discontinued
Dimensions
A4
124.8 x 66 x 9.5 mm (4.91 x 2.60 x 0.37 in)
KT21 Express
-
Weight
A4
75 g (2.65 oz)
KT21 Express
-
SIM
A4
Dual SIM (Mini-SIM)
KT21 Express
Dual SIM (Mini-SIM)
Type
A4
TFT, 256K colors
KT21 Express
TFT
Size
A4
4.0 inches, 47.6 cm2 (~57.8% screen-to-body ratio)
KT21 Express
2.8 inches, 24.3 cm2
Resolution
A4
320 x 480 pixels, 3:2 ratio (~144 ppi density)
KT21 Express
240 x 320 pixels, 4:3 ratio
OS
A4
Android 2.3.6 (Gingerbread)
KT21 Express
-
Card slot
A4
microSDHC (dedicated slot)
KT21 Express
microSDHC (dedicated slot)
Internal
A4
256MB 512MB
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
Single
A4
Yes
KT21 Express
-
Video
A4
KT21 Express
-
Other
A4
-
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, hotspot
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
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 1400 mAh battery
KT21 Express
Li-Ion 1000 mAh, removable
Stand-by
A4
Up to 250 h
KT21 Express
-
Talk time
A4
Up to 4 h 20 min
KT21 Express
-
Colors
A4
White/Black
KT21 Express
Black
Price
A4
About 70 EUR
KT21 Express
About 40 EUR