Screen size
U3100Winner: 2.0"+9%
Watch Fit 41.8"
Quick verdict
Watch Fit 4 leads the measured specs 8-4.
Measured wins
U3100
4
spec wins
Ties
2
equal specs
Watch Fit 4
8
spec wins
Overall winner
Screen size
Technology
U3100
GSM / UMTS
Watch Fit 4
No cellular connectivity
2G bands
U3100
GSM 900 / 1800 / 1900
Watch Fit 4
N/A
3G bands
U3100
UMTS 2100
Watch Fit 4
N/A
Speed
U3100
Yes, 384 kbps
Watch Fit 4
Resolution
Refresh rate
Peak brightness
Pixel density
CPU speed
RAM
Storage
Main camera
Front camera
Battery
Wired charging
Weight
Thickness
IP rating
Wi‑Fi
Bluetooth
USB
5G support
equal specsNFC
3.5mm jack
equal specsSD card
Stereo speakers
No
4G bands
U3100
-
Watch Fit 4
N/A
GPRS
U3100
-
Watch Fit 4
No
EDGE
U3100
-
Watch Fit 4
No
Announced
U3100
2010. Released 2010
Watch Fit 4
2025, May 15
Status
U3100
Discontinued
Watch Fit 4
Available. Released 2025, May 26
Dimensions
U3100
106 x 46 x 13 mm (4.17 x 1.81 x 0.51 in)
Watch Fit 4
43 x 38 x 9.5 mm (1.69 x 1.50 x 0.37 in)
Weight
U3100
90 g (3.17 oz)
Watch Fit 4
27 g (0.95 oz)
SIM
U3100
Mini-SIM
Watch Fit 4
No
Build
U3100
-
Watch Fit 4
Glass front, aluminum alloy frame, plastic back
Other
U3100
-
Watch Fit 4
5 ATM water resistant
Type
U3100
TFT, 256K colors
Watch Fit 4
AMOLED, 2000 nits (peak)
Size
U3100
2.0 inches, 12.4 cm2 (~25.4% screen-to-body ratio)
Watch Fit 4
1.82 inches
Resolution
U3100
240 x 320 pixels, 4:3 ratio (~200 ppi density)
Watch Fit 4
480 x 408 pixels (~347 ppi density)
Card slot
U3100
microSDHC (dedicated slot)
Watch Fit 4
No
Phonebook
U3100
Yes, Photocall
Watch Fit 4
No
Call records
U3100
Yes
Watch Fit 4
No
Internal
U3100
10MB
Watch Fit 4
Unspecified
Single
U3100
VGA
Watch Fit 4
-
Video
U3100
Yes
Watch Fit 4
-
Single
U3100
Yes
Watch Fit 4
-
Video
U3100
Watch Fit 4
-
Loudspeaker
U3100
Yes
Watch Fit 4
Yes
3.5mm jack
U3100
No
Watch Fit 4
No
WLAN
U3100
No
Watch Fit 4
No
Bluetooth
U3100
2.0, EDR
Watch Fit 4
5.2, LE
Positioning
U3100
GPS, A-GPS
Watch Fit 4
GPS (L1+L5), GALILEO (E1+E5a), QZSS (L1+L5), BDS (B1l+B1C), GLONASS
Radio
U3100
FM Radio
Watch Fit 4
No
USB
U3100
miniUSB 2.0
Watch Fit 4
No
NFC
U3100
-
Watch Fit 4
Yes (gray model only)
Sensors
U3100
Watch Fit 4
Accelerometer, gyro, heart rate, SpO2, compass, barometer
Messaging
U3100
SMS(threaded view), MMS, Email, IM
Watch Fit 4
Email, IM
Browser
U3100
HTML
Watch Fit 4
-
Games
U3100
Yes
Watch Fit 4
No
Java
U3100
Yes
Watch Fit 4
No
Other
U3100
MP3/eAAC+ player MP4/H.264 player Voice memo Predictive text input
Watch Fit 4
Pulse wave arrhythmia analysis
Type
U3100
Removable Li-Ion 1000 mAh battery
Watch Fit 4
Li-Ion 400 mAh
Stand-by
U3100
Up to 400 h
Watch Fit 4
-
Talk time
U3100
Up to 4 h 20 min
Watch Fit 4
-
Charging
U3100
-
Watch Fit 4
5W wireless
Colors
U3100
Black
Watch Fit 4
Black, Silver
Models
U3100
-
Watch Fit 4
SYA-B19
Price
U3100
-
Watch Fit 4
$ 121.00 / € 104.76
Other
U3100
-
Watch Fit 4
No