Apple Watch Series 2 (38mm) vs Apple Watch Series 4 (40mm) Specs Comparison

Compare mobile phone specifications of up to three devices at once. Our specs comparison tool helps you find and compare the perfect phone for your needs.

Apple Watch Series 2 (38mm) Apple Watch Series 4 (40mm)
Released · September 2016
Released · September 2018
1.5-inch · 340 x 272 px
1.6-inch · 394 x 324 px
0.5GB · 8GB
1GB · 16GB
273 mAh
225 mAh

Display

Size
1.5-inch 1.6-inch
Resolution
340 x 272 px, 290 PPI 394 x 324 px, 325 PPI
Technology
OLED OLED
Screen-to-body
55.12 % 57.48 %
Peak brightness
1000 cd/m2 (nit) 1000 cd/m2 (nit)
Features
Pressure-sensitive, Ambient light sensor Pressure-sensitive, Scratch-resistant glass (Sapphire), Ambient light sensor

Hardware

System chip
Apple S2 (16 nm) Apple S4 (7 nm)
Processor
Dual-core, 780 MHz, Cortex-A7 Dual-core
GPU
PowerVR G6200 Apple G11M
RAM
0.5GB 1GB
Internal storage
8GB, not expandable 16GB, not expandable
OS
watchOS (6.x, 5.1, 5, 4.x, 3.x) watchOS (9.x, 8.x, 7.x, 6.x, 5)
Device type
Smartwatch Smartwatch

Battery

Capacity
273 mAh 225 mAh
Type
Not user replaceable Not user replaceable
Charging
Magnetic charging Magnetic charging

Camera

Design

Dimensions
1.52 x 1.31 x 0.45 inches
(38.6 x 33.3 x 11.4 mm)
1.57 x 1.34 x 0.42 inches
(40.0 x 34.0 x 10.7 mm)
Weight
1.48 oz(41.9 g) 1.06 oz(30.1 g)
Materials
Frame: Stainless steel Frame: Aluminum
Resistance
Water Water
Colors
Silver, Black Silver, Black

Cellular

Data Speed
LTE, HSPA
SIM type
eSIM

Multimedia

Speakers
Loudspeaker Loudspeaker
Additional microphone(s)
Noise cancellation

Connectivity & Features

Bluetooth
4.0 5.0
Wi-Fi
802.11 b,g,n 802.11 b,g,n
Location
Glonass, Galileo Glonass, Galileo, QZSS
Sensors
Accelerometer, Gyroscope, Heart rate Accelerometer, Gyroscope, Heart rate, Barometer
Other
NFC NFC

Alternative variants

With aluminum frame
Weight 0.99 oz(28.2 g)
Materials Frame: Aluminum
With stainless steel case
Weight 1.40 oz(39.8 g)
Materials Frame: Stainless steel
FCC OKs Cingular\'s purchase of AT&T Wireless