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

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 Aluminum frame - 28.2 g	1.06 oz / 30.1 g Stainless steel case - 39.8 g
Materials
Frame: Stainless steel	Frame: Aluminum
Resistance
Water	Water
Colors
Silver, Black	Silver, Black

Display

Size
1.5-inch, 55.12% screen-to-body	1.6-inch, 57.48% screen-to-body
Type
OLED, 1000 nits	OLED, 1000 nits
Resolution
340x272px, 290 PPI	394x324px, 325 PPI
Protection
	Sapphire
Features
Pressure-sensitive, Ambient light sensor	Pressure-sensitive, Scratch-resistant glass, 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
Memory
0.5GB/8GB	1GB/16GB
Storage expansion
not expandable	not expandable
OS
watchOS (6.x, 5.1, 5, 4.x, 3.x)	watchOS (9.x, 8.x, 7.x, 6.x, 5)

Battery

Type
273 mAh	225 mAh
Charging
Magnetic charging	Magnetic charging

Connectivity & Features

Bluetooth
4.0	5.0
WLAN
Yes 802.11 b, g, n	Yes 802.11 b, g, n
Sensors
Accelerometer, Gyroscope, Heart rate, Ambient light sensor	Accelerometer, Gyroscope, Heart rate, Barometer, Ambient light sensor
Location
Glonass, Galileo	Glonass, Galileo, QZSS
Other
NFC	NFC

Multimedia

Speakers
Loudspeaker	Loudspeaker
Additional microphone(s)
	Noise cancellation

Cellular

Data Speed
	LTE, HSPA
SIM type
	eSIM

Discover more

Full Specs Apple Watch Series 2 (38mm) Specs

Full Specs Apple Watch Series 4 (40mm) Specs