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The SIM stores your account information and connects your device to the T‑Mobile network.
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Key features
326 pixels
Always-On Retina display with OLED and LTPO
Talk Time
18 Hours Standby Time
Other features
- Health essentials¹˒⁴˒⁵˒⁶
- Great battery Life ²
- Always on Display
- A Great Fitness Partner⁸
- Stay Connected
- Safety Features ⁹
- Apple watch for your kids¹⁰
Apple Watch SE 3 is packed with health, fitness, connectivity, and safety essentials—all for a great value. Track your sleep score. Get richer health insights in the Vitals app.1 Stay active with a wide range of workouts. Save time with fast charging.2 See your info at a glance with the Always-On display. And still get all-day, 18-hour battery life.3
Need help with choosing which Apple Watch is right for you? Apple Watch comparison chart to help you decide based on features and options for each smartwatch side-by-side.
Get our best Apple Deals on the newest iPhones, newest iPads and Apple Watches Also, be sure to explore the stunning new Apple Watch SE 3 44mm, Apple Watch Series 11 42mm , Apple Watch Series 11 46mm and Apple Watch Ultra 3 , available on the nation’s largest and fastest nationwide 5G network.
Apple Watch SE 3 40mm Quick Facts
1The Vitals app is for wellness purposes only and not for medical use.
2Fast charging is compatible with Apple Watch Series 7 and later, any Apple Watch Ultra model, and Apple Watch SE 3.
3Battery life varies by use and configuration. See apple.com/watch/battery for more information.
4The temperature sensing feature is not intended for medical use. Temperature sensing is available only on Apple Watch Series 8 and later and all Apple Watch Ultra models.
5Sleep apnea notifications are available on Apple Watch Series 9 and later, Ultra 2 and later, and SE 3. The feature is intended to detect signs of moderate to severe sleep apnea for people 18 years old or older without a diagnosis of sleep apnea.
6Irregular rhythm notification requires the latest versions of watchOS and iOS. It is not intended for use by people under 22 years old or those who have been previously diagnosed with atrial fibrillation (AFib).
7Testing conducted by Apple in July and August 2025 using preproduction Apple Watch SE 3 (GPS + Cellular) and Apple Watch SE 2 (GPS + Cellular), each paired with an iPhone; all devices tested with prerelease software, Apple Watch Magnetic Fast Charger to USB-C Cable (Model A2515), and Apple 20W USB-C Power Adapter (Model A2305). Charge time varies with adapter, region, settings, initial battery levels, usage, and environmental factors; actual results will vary.
8Requires an Apple Intelligence–enabled iPhone nearby and Bluetooth headphones with device and Siri language set to English. Apple Intelligence is available in beta. Some features may not be available in all regions or languages. For feature and language availability and system requirements, see support.apple.com/en-us/121115.
9Emergency SOS requires a cellular connection orWi-Fi calling with an internet connection from your Apple Watch or nearby iPhone. You can use cellular models of Apple Watch to make an emergency call in many locations, provided that cellular service is available. Some cellular networks may not accept an emergency callfrom your Apple Watch if your Apple Watch isn’t activated, if it isn’t compatible with or configured to operate on a particular cellular network, if isn’t set up for cellular service, or if the cellular network does not support emergency calling over IMS. See support.apple.com/108374 and apple.com/watch/cellular for more information.
10Not all features will be available if the Apple Watch is set up through Apple Watch For Your Kids. Check support.apple.com/en-us/109036 for details. Wireless service plan required for cellular service. Check apple.com/watch/cellular for participating wireless carriers and eligibility.
11Wireless service plan required for cellular service. Contact your service provider for more details. Connection may vary based on network availability. Check apple.com/watch/cellular for participating wireless carriers and eligibility. See support.apple.com/HT207578 for additional setup instructions.
12Data plan required. 5G is available in select markets and through select carriers. Speeds vary based on site conditions and carrier. For details on 5G support, contact your carrier and see apple.com/watch/cellular.
Need help with choosing which Apple Watch is right for you? Apple Watch comparison chart to help you decide based on features and options for each smartwatch side-by-side.
Get our best Apple Deals on the newest iPhones, newest iPads and Apple Watches Also, be sure to explore the stunning new Apple Watch SE 3 44mm, Apple Watch Series 11 42mm , Apple Watch Series 11 46mm and Apple Watch Ultra 3 , available on the nation’s largest and fastest nationwide 5G network.
Apple Watch SE 3 40mm Quick Facts
- When will the Apple Watch SE 3 40mm be released? The Apple Watch SE 3 40mm will be released on September 19th, 2025, with the ability to pre-order on September 12th, 2025.
- What colors will be available for the Apple Watch SE 3 40mm? The Apple Watch SE 3 40mm will be available in 2 colors: Starlight Aluminum, and Midnight Aluminum, and can be customized with colorful watch bands.
1The Vitals app is for wellness purposes only and not for medical use.
2Fast charging is compatible with Apple Watch Series 7 and later, any Apple Watch Ultra model, and Apple Watch SE 3.
3Battery life varies by use and configuration. See apple.com/watch/battery for more information.
4The temperature sensing feature is not intended for medical use. Temperature sensing is available only on Apple Watch Series 8 and later and all Apple Watch Ultra models.
5Sleep apnea notifications are available on Apple Watch Series 9 and later, Ultra 2 and later, and SE 3. The feature is intended to detect signs of moderate to severe sleep apnea for people 18 years old or older without a diagnosis of sleep apnea.
6Irregular rhythm notification requires the latest versions of watchOS and iOS. It is not intended for use by people under 22 years old or those who have been previously diagnosed with atrial fibrillation (AFib).
7Testing conducted by Apple in July and August 2025 using preproduction Apple Watch SE 3 (GPS + Cellular) and Apple Watch SE 2 (GPS + Cellular), each paired with an iPhone; all devices tested with prerelease software, Apple Watch Magnetic Fast Charger to USB-C Cable (Model A2515), and Apple 20W USB-C Power Adapter (Model A2305). Charge time varies with adapter, region, settings, initial battery levels, usage, and environmental factors; actual results will vary.
8Requires an Apple Intelligence–enabled iPhone nearby and Bluetooth headphones with device and Siri language set to English. Apple Intelligence is available in beta. Some features may not be available in all regions or languages. For feature and language availability and system requirements, see support.apple.com/en-us/121115.
9Emergency SOS requires a cellular connection or
10Not all features will be available if the Apple Watch is set up through Apple Watch For Your Kids. Check support.apple.com/en-us/109036 for details. Wireless service plan required for cellular service. Check apple.com/watch/cellular for participating wireless carriers and eligibility.
11Wireless service plan required for cellular service. Contact your service provider for more details. Connection may vary based on network availability. Check apple.com/watch/cellular for participating wireless carriers and eligibility. See support.apple.com/HT207578 for additional setup instructions.
12Data plan required. 5G is available in select markets and through select carriers. Speeds vary based on site conditions and carrier. For details on 5G support, contact your carrier and see apple.com/watch/cellular.
What’s in the box
- Apple Watch SE 3 40mm
- Band
- Apple Watch Magnetic Fast Charger to USB-C Cable (1m)
Additional spec details
Battery Description
Built-in rechargeable lithium-ion battery
Ports
Magnetic Charger to USB-C Cable
Connectivity
Processor
S10 chip with 64‑bit dual core processor
Operating System
watchOS
Maximum Expandable Memory
0 GB
Wireless Network Technology Generations
4G LTE, 5G
Supported Email Platforms
Apple Mail, POP3, IMAP4, SMTP, Microsoft® Exchange, AOL, AIM, Yahoo!® Mail, GMail
WEA Capable
true
Mobile Hotspot Capable
true
Frequency
LTE: 1, 2, 3, 4, 5, 7, 8, 12, 13, 14, 17, 18, 19, 20, 25, 26, 28, 38, 40, 41, 66, 71; 5G: n1, n2, n3, n5, n7, n8, n12, n14, n20, n25, n26, n28, n66, n71
Weight
0.93 Ounces
Length
0.42 Inches
Height
1.57 Inches
Width
1.49 Inches
Loading reviews
Key features
326 pixels
Always-On Retina display with OLED and LTPO
Talk Time
18 Hours Standby Time
Other features
- Health essentials¹˒⁴˒⁵˒⁶
- Great battery Life ²
- Always on Display
- A Great Fitness Partner⁸
- Stay Connected
- Safety Features ⁹
- Apple watch for your kids¹⁰
Apple Watch SE 3 is packed with health, fitness, connectivity, and safety essentials—all for a great value. Track your sleep score. Get richer health insights in the Vitals app.1 Stay active with a wide range of workouts. Save time with fast charging.2 See your info at a glance with the Always-On display. And still get all-day, 18-hour battery life.3
Need help with choosing which Apple Watch is right for you? Apple Watch comparison chart to help you decide based on features and options for each smartwatch side-by-side.
Get our best Apple Deals on the newest iPhones, newest iPads and Apple Watches Also, be sure to explore the stunning new Apple Watch SE 3 44mm, Apple Watch Series 11 42mm , Apple Watch Series 11 46mm and Apple Watch Ultra 3 , available on the nation’s largest and fastest nationwide 5G network.
Apple Watch SE 3 40mm Quick Facts
1The Vitals app is for wellness purposes only and not for medical use.
2Fast charging is compatible with Apple Watch Series 7 and later, any Apple Watch Ultra model, and Apple Watch SE 3.
3Battery life varies by use and configuration. See apple.com/watch/battery for more information.
4The temperature sensing feature is not intended for medical use. Temperature sensing is available only on Apple Watch Series 8 and later and all Apple Watch Ultra models.
5Sleep apnea notifications are available on Apple Watch Series 9 and later, Ultra 2 and later, and SE 3. The feature is intended to detect signs of moderate to severe sleep apnea for people 18 years old or older without a diagnosis of sleep apnea.
6Irregular rhythm notification requires the latest versions of watchOS and iOS. It is not intended for use by people under 22 years old or those who have been previously diagnosed with atrial fibrillation (AFib).
7Testing conducted by Apple in July and August 2025 using preproduction Apple Watch SE 3 (GPS + Cellular) and Apple Watch SE 2 (GPS + Cellular), each paired with an iPhone; all devices tested with prerelease software, Apple Watch Magnetic Fast Charger to USB-C Cable (Model A2515), and Apple 20W USB-C Power Adapter (Model A2305). Charge time varies with adapter, region, settings, initial battery levels, usage, and environmental factors; actual results will vary.
8Requires an Apple Intelligence–enabled iPhone nearby and Bluetooth headphones with device and Siri language set to English. Apple Intelligence is available in beta. Some features may not be available in all regions or languages. For feature and language availability and system requirements, see support.apple.com/en-us/121115.
9Emergency SOS requires a cellular connection orWi-Fi calling with an internet connection from your Apple Watch or nearby iPhone. You can use cellular models of Apple Watch to make an emergency call in many locations, provided that cellular service is available. Some cellular networks may not accept an emergency callfrom your Apple Watch if your Apple Watch isn’t activated, if it isn’t compatible with or configured to operate on a particular cellular network, if isn’t set up for cellular service, or if the cellular network does not support emergency calling over IMS. See support.apple.com/108374 and apple.com/watch/cellular for more information.
10Not all features will be available if the Apple Watch is set up through Apple Watch For Your Kids. Check support.apple.com/en-us/109036 for details. Wireless service plan required for cellular service. Check apple.com/watch/cellular for participating wireless carriers and eligibility.
11Wireless service plan required for cellular service. Contact your service provider for more details. Connection may vary based on network availability. Check apple.com/watch/cellular for participating wireless carriers and eligibility. See support.apple.com/HT207578 for additional setup instructions.
12Data plan required. 5G is available in select markets and through select carriers. Speeds vary based on site conditions and carrier. For details on 5G support, contact your carrier and see apple.com/watch/cellular.
Need help with choosing which Apple Watch is right for you? Apple Watch comparison chart to help you decide based on features and options for each smartwatch side-by-side.
Get our best Apple Deals on the newest iPhones, newest iPads and Apple Watches Also, be sure to explore the stunning new Apple Watch SE 3 44mm, Apple Watch Series 11 42mm , Apple Watch Series 11 46mm and Apple Watch Ultra 3 , available on the nation’s largest and fastest nationwide 5G network.
Apple Watch SE 3 40mm Quick Facts
- When will the Apple Watch SE 3 40mm be released? The Apple Watch SE 3 40mm will be released on September 19th, 2025, with the ability to pre-order on September 12th, 2025.
- What colors will be available for the Apple Watch SE 3 40mm? The Apple Watch SE 3 40mm will be available in 2 colors: Starlight Aluminum, and Midnight Aluminum, and can be customized with colorful watch bands.
1The Vitals app is for wellness purposes only and not for medical use.
2Fast charging is compatible with Apple Watch Series 7 and later, any Apple Watch Ultra model, and Apple Watch SE 3.
3Battery life varies by use and configuration. See apple.com/watch/battery for more information.
4The temperature sensing feature is not intended for medical use. Temperature sensing is available only on Apple Watch Series 8 and later and all Apple Watch Ultra models.
5Sleep apnea notifications are available on Apple Watch Series 9 and later, Ultra 2 and later, and SE 3. The feature is intended to detect signs of moderate to severe sleep apnea for people 18 years old or older without a diagnosis of sleep apnea.
6Irregular rhythm notification requires the latest versions of watchOS and iOS. It is not intended for use by people under 22 years old or those who have been previously diagnosed with atrial fibrillation (AFib).
7Testing conducted by Apple in July and August 2025 using preproduction Apple Watch SE 3 (GPS + Cellular) and Apple Watch SE 2 (GPS + Cellular), each paired with an iPhone; all devices tested with prerelease software, Apple Watch Magnetic Fast Charger to USB-C Cable (Model A2515), and Apple 20W USB-C Power Adapter (Model A2305). Charge time varies with adapter, region, settings, initial battery levels, usage, and environmental factors; actual results will vary.
8Requires an Apple Intelligence–enabled iPhone nearby and Bluetooth headphones with device and Siri language set to English. Apple Intelligence is available in beta. Some features may not be available in all regions or languages. For feature and language availability and system requirements, see support.apple.com/en-us/121115.
9Emergency SOS requires a cellular connection or
10Not all features will be available if the Apple Watch is set up through Apple Watch For Your Kids. Check support.apple.com/en-us/109036 for details. Wireless service plan required for cellular service. Check apple.com/watch/cellular for participating wireless carriers and eligibility.
11Wireless service plan required for cellular service. Contact your service provider for more details. Connection may vary based on network availability. Check apple.com/watch/cellular for participating wireless carriers and eligibility. See support.apple.com/HT207578 for additional setup instructions.
12Data plan required. 5G is available in select markets and through select carriers. Speeds vary based on site conditions and carrier. For details on 5G support, contact your carrier and see apple.com/watch/cellular.
What’s in the box
- Apple Watch SE 3 40mm
- Band
- Apple Watch Magnetic Fast Charger to USB-C Cable (1m)
Additional spec details
Battery Description
Built-in rechargeable lithium-ion battery
Ports
Magnetic Charger to USB-C Cable
Connectivity
Processor
S10 chip with 64‑bit dual core processor
Operating System
watchOS
Maximum Expandable Memory
0 GB
Wireless Network Technology Generations
4G LTE, 5G
Supported Email Platforms
Apple Mail, POP3, IMAP4, SMTP, Microsoft® Exchange, AOL, AIM, Yahoo!® Mail, GMail
WEA Capable
true
Mobile Hotspot Capable
true
Frequency
LTE: 1, 2, 3, 4, 5, 7, 8, 12, 13, 14, 17, 18, 19, 20, 25, 26, 28, 38, 40, 41, 66, 71; 5G: n1, n2, n3, n5, n7, n8, n12, n14, n20, n25, n26, n28, n66, n71
Weight
0.93 Ounces
Length
0.42 Inches
Height
1.57 Inches
Width
1.49 Inches
