Screen size
EF51Winner: 2.2"+9.1%
S812.0"
Quick verdict
S81 leads the measured specs 4-3.
Measured wins
EF51
3
spec wins
Ties
4
equal specs
S81
4
spec wins
Overall winner
Screen size
Technology
EF51
GSM
S81
GSM / UMTS
2G bands
EF51
GSM 900 / 1800 / 1900 , GSM 850 / 1800 / 1900 - US version
S81
GSM 900 / 1800 / 1900
GPRS
EF51
Class 10
S81
-
EDGE
EF51
No
S81
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
3.5mm jack
equal specsSD card
equal specsStereo speakers
-
3G bands
EF51
-
S81
UMTS 2100
Speed
EF51
-
S81
Yes, 384 kbps
Announced
EF51
2006, February
S81
2006, February
Status
EF51
Discontinued
S81
Discontinued
Dimensions
EF51
89 x 49 x 18 mm (3.50 x 1.93 x 0.71 in)
S81
109 x 48 x 13 mm (4.29 x 1.89 x 0.51 in)
Weight
EF51
95 g (3.35 oz)
S81
99 g (3.49 oz)
SIM
EF51
Mini-SIM
S81
Mini-SIM
Type
EF51
TFT, 256K colors
S81
TFT, 256K colors
Size
EF51
2.2 inches, 40 x 40 mm, 15.6 cm2 (~35.7% screen-to-body ratio)
S81
2.0 inches, 31 x 39 mm, 12.6 cm2 (~24.1% screen-to-body ratio)
Resolution
EF51
120 x 128 pixels (~80 ppi density)
S81
176 x 220 pixels (~141 ppi density)
Card slot
EF51
miniSD
S81
microSD (dedicated slot)
Phonebook
EF51
Yes, Photo call
S81
Yes, Photo call
Call records
EF51
10 dialed, 10 received, 10 missed calls
S81
10 dialed, 10 received, 10 missed calls
Internal
EF51
20MB
S81
30MB
Single
EF51
1.3 MP
S81
1.3 MP
Video
EF51
No
S81
Yes
Features
EF51
-
S81
LED flash
Other
EF51
No
S81
-
Single
EF51
-
S81
VGA videocall camera
Video
EF51
-
S81
Loudspeaker
EF51
No
S81
No
Alert types
EF51
Vibration; Downloadable polyphonic, MP3 ringtones
S81
Vibration; Downloadable polyphonic, MP3, AAC ringtones
3.5mm jack
EF51
No
S81
No
Other
EF51
3D surround sound
S81
-
WLAN
EF51
No
S81
No
Bluetooth
EF51
1.2, A2DP
S81
1.1
Positioning
EF51
No
S81
No
Radio
EF51
FM radio
S81
No
USB
EF51
Proprietary
S81
Proprietary
Sensors
EF51
S81
Messaging
EF51
SMS, MMS
S81
SMS, MMS, Email
Browser
EF51
WAP 2.0/xHTML
S81
WAP 2.0/xHTML
Games
EF51
Yes + downloadable
S81
Yes
Java
EF51
Yes, MIDP 2.0
S81
Yes, MIDP 2.0
Other
EF51
WMA/MP3/AAC/AAC+ player Predictive text input Voice memo Stopwatch Organizer
S81
MP3/AAC player Video telephony iTap Stopwatch Organizer
Type
EF51
Removable Li-Ion 870 mAh battery
S81
Removable Li-Ion 920 mAh battery
Stand-by
EF51
Up to 200 h
S81
Up to 320 h
Talk time
EF51
Up to 4 h
S81
Up to 4 h 50 min
Colors
EF51
Flashy White, Black
S81
Black/Silver