Screen size
U8100Winner: 2.8"+35%
Watch Fit 41.8"
Quick verdict
Watch Fit 4 leads the measured specs 8-6.
Measured wins
U8100
6
spec wins
Ties
1
equal specs
Watch Fit 4
8
spec wins
Overall winner
Screen size
Technology
U8100
GSM / HSPA
Watch Fit 4
No cellular connectivity
2G bands
U8100
GSM 900 / 1800 / 1900
Watch Fit 4
N/A
3G bands
U8100
HSDPA 900 / 2100
Watch Fit 4
N/A
Speed
U8100
HSPA 7.2/0.384 Mbps
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
SD card
Stereo speakers
No
4G bands
U8100
-
Watch Fit 4
N/A
GPRS
U8100
-
Watch Fit 4
No
EDGE
U8100
-
Watch Fit 4
No
Announced
U8100
2010, February. Released 2010, July
Watch Fit 4
2025, May 15
Status
U8100
Discontinued
Watch Fit 4
Available. Released 2025, May 26
Dimensions
U8100
107.5 x 57 x 13.8 mm (4.23 x 2.24 x 0.54 in)
Watch Fit 4
43 x 38 x 9.5 mm (1.69 x 1.50 x 0.37 in)
Weight
U8100
104 g (3.67 oz)
Watch Fit 4
27 g (0.95 oz)
SIM
U8100
Mini-SIM
Watch Fit 4
No
Build
U8100
-
Watch Fit 4
Glass front, aluminum alloy frame, plastic back
Other
U8100
-
Watch Fit 4
5 ATM water resistant
Type
U8100
TFT, 256K colors
Watch Fit 4
AMOLED, 2000 nits (peak)
Size
U8100
2.8 inches, 24.3 cm2 (~39.6% screen-to-body ratio)
Watch Fit 4
1.82 inches
Resolution
U8100
240 x 320 pixels, 4:3 ratio (~143 ppi density)
Watch Fit 4
480 x 408 pixels (~347 ppi density)
Other
U8100
Watch Fit 4
-
OS
U8100
Android 2.1 (Eclair)
Watch Fit 4
-
Card slot
U8100
microSDHC (dedicated slot)
Watch Fit 4
No
Phonebook
U8100
-
Watch Fit 4
No
Call records
U8100
-
Watch Fit 4
No
Internal
U8100
-
Watch Fit 4
Unspecified
Single
U8100
3.15 MP
Watch Fit 4
-
Features
U8100
LED flash
Watch Fit 4
-
Video
U8100
Yes
Watch Fit 4
-
Single
U8100
VGA
Watch Fit 4
-
Video
U8100
Watch Fit 4
-
Loudspeaker
U8100
Yes
Watch Fit 4
Yes
3.5mm jack
U8100
Yes
Watch Fit 4
No
WLAN
U8100
Wi-Fi 802.11 b/g
Watch Fit 4
No
Bluetooth
U8100
2.0, A2DP
Watch Fit 4
5.2, LE
Positioning
U8100
GPS, A-GPS
Watch Fit 4
GPS (L1+L5), GALILEO (E1+E5a), QZSS (L1+L5), BDS (B1l+B1C), GLONASS
Radio
U8100
FM radio
Watch Fit 4
No
USB
U8100
microUSB 2.0
Watch Fit 4
No
NFC
U8100
-
Watch Fit 4
Yes (gray model only)
Sensors
U8100
Accelerometer
Watch Fit 4
Accelerometer, gyro, heart rate, SpO2, compass, barometer
Browser
U8100
HTML
Watch Fit 4
-
Other
U8100
MP3/WAV/WMA/eAAC+ player MP4/WMV/H.264 player Document viewer Voice memo Predictive text input
Watch Fit 4
Pulse wave arrhythmia analysis
Messaging
U8100
-
Watch Fit 4
Email, IM
Games
U8100
-
Watch Fit 4
No
Java
U8100
-
Watch Fit 4
No
Type
U8100
Removable Li-Ion 1150 mAh battery
Watch Fit 4
Li-Ion 400 mAh
Stand-by
U8100
Up to 240 h
Watch Fit 4
-
Talk time
U8100
Up to 4 h 30 min
Watch Fit 4
-
Charging
U8100
-
Watch Fit 4
5W wireless
Colors
U8100
Pink
Watch Fit 4
Black, Silver
SAR
U8100
0.76 W/kg (head) 0.86 W/kg (body)
Watch Fit 4
-
SAR EU
U8100
0.68 W/kg (head)
Watch Fit 4
-
Price
U8100
About 70 EUR
Watch Fit 4
$ 121.00 / € 104.76
Models
U8100
-
Watch Fit 4
SYA-B19
Other
U8100
-
Watch Fit 4
No