Full specifications, features and battery life for the Apple Watch SE 3, the brand’s entry-level model.
| Manufacturer | Apple |
| Type | Smartwatch, entry-level tier |
| Series | Watch SE |
| Released | September 2025 |
| Price at launch | From $249 / £219 |
| Predecessor | Apple Watch SE 2 |
| Successor | – |
| Case sizes | 40mm, 44mm |
| Thickness | 10.7mm |
| Weight | 26.3–26.4g (40mm), 32.9–33.0g (44mm) |
| Materials | Aluminium: Midnight, Starlight |
| Water resistance | 50m |
Specifications and features as at launch.
Apple Watch SE 3
Smart fitness watch
Expert opinion | What’s new | Specifications | Battery life | Features | Software updates | Quick answers | Further reading
Expert opinion
The SE 3 carries the same S10 chip as Series 11 and Ultra 3, and gains an always-on Retina display for the first time on an SE model, rated up to 1,000 nits. Double-tap and wrist-flick gestures, on-device Siri, wrist temperature sensing, Sleep Score and cycle tracking with ovulation estimates all arrive on the entry-level tier for the first time. Storage doubles to 64GB, fast charging is added, and 5G is available as an option. The case stays aluminium only, in 40mm or 44mm, with 50-metre water resistance. Apple claims up to 18 hours of battery life. The SE 3 has no ECG and no blood oxygen sensor, and keeps the thicker glass design rather than the flatter profile of Series 10 and 11.
What’s new versus Apple Watch SE 2
- Always-On display, replacing the SE 2’s standard-refresh panel; glass rated 4x more crack-resistant
- New S10 chip, from the S8 SiP
- Storage doubles to 64GB, from 32GB
- New wrist temperature sensor, enabling cycle tracking with retrospective ovulation estimates and a Sleep Score
- 5G and LTE connectivity, replacing 4G LTE and UMTS
- Fast charging added: up to 80% in about 45 minutes. The SE 2 had no fast charging.
- Low Power Mode added, claimed up to 32 hours
- Double-tap and wrist flick gestures added; the SE 2 had neither
- Siri gains on-device processing
The optical heart rate sensor is unchanged, carried over from the SE 2 as the same second-generation design.
Specifications
| Display | |
|---|---|
| Type | Always-On Retina, OLED, LTPO |
| Peak brightness | Up to 1,000 nits |
| Glass | 4x more crack-resistant than the SE 2 |
| Internals | |
| Chip | S10, 64-bit dual-core processor |
| Storage | 64GB |
| Sensors | |
| Heart rate | Second-generation optical sensor |
| Temperature | Wrist temperature sensor |
| Other | Compass, always-on altimeter, high-g accelerometer, high dynamic range gyroscope, ambient light sensor |
| © the5krunner. Link required. | |
| Connectivity and battery | |
| Positioning | L1 GPS, GNSS, Galileo, QZSS |
| Cellular | 5G and LTE |
| Wireless | WiFi 4 (802.11n), Bluetooth 5.3 |
| Fast charging | Up to 80% in about 45 minutes |
| Battery, normal use | Up to 18 hours |
| Battery, Low Power Mode | Up to 32 hours |
Battery life
Apple claims up to 18 hours of normal use, unchanged from the SE 2, with a new Low Power Mode extending that to up to 32 hours. Fast charging is new to this generation: up to 80% in around 45 minutes.
Features
Full feature detail is covered on the Apple specifications index.
Health and wellness
- Cycle tracking with retrospective ovulation estimates, enabled by the new temperature sensor
- Sleep Score, plus sleep stage tracking
- Sleep apnea notifications
- Heart Rate app, with high and low heart rate notifications and irregular rhythm notifications
- Medications, Mindfulness and Noise apps
Interface
- Double-tap gesture, for hands-free control
- Wrist flick gesture
- Siri with on-device processing
Apple Watch SE 3 software updates
The current Apple Watch SE 3 software is watchOS 27.2.1. Apple is still updating the Watch SE 3, with 4 software releases since September 2026. This section is updated when Apple releases a new version.
| Current version | watchOS 27.2.1, released 9 November 2026. |
| Last update | watchOS 27.2.1 on 9 November 2026. |
Features added since September 2026
- watchOS 27.2, 26 October 2026. Siri AI remembers past conversations, uses more information from iPhone, responds faster on the watch and adds French, Japanese, Korean, Portuguese and Spanish. Siri AI is not available in the EU or mainland China.
- watchOS 27, 14 September 2026.
- Siri AI: a more conversational Siri using personal context, app actions and onscreen awareness
- A dedicated Siri app with conversations synced through iCloud, plus a Siri complication
- Workout Buddy works without a nearby iPhone, over Wi-Fi or mobile data
- Cycle deviation notifications suggestive of perimenopause for users aged 40 and over
- Siri Modular watch face and single-handed tap to select Smart Stack widgets
- A dynamic app grid and a single Find My app
- Offline Shazam song recognition, plus more accurate treadmill distance and route maps
Full version history, 4 releases including betas and fixes
| Version | Type | Date | What changed |
|---|---|---|---|
| watchOS 27.2.1 | Stable | 9 November 2026 | Security and bug fixes. |
| watchOS 27.2 | Stable | 26 October 2026 | Siri AI remembers past conversations, uses more information from iPhone, responds faster on the watch and adds French, Japanese, Korean, Portuguese and Spanish. Siri AI is not available in the EU or mainland China. |
| watchOS 27.0.1 | Stable | 28 September 2026 | Bug fixes, including a fix for the watch restarting unexpectedly. |
| watchOS 27 | Stable | 14 September 2026 | Major update bringing Siri AI with its own Siri app, Workout Buddy without an iPhone, perimenopause cycle notifications and a dynamic app grid. |
Version history is recorded from September 2026. See also known problems and fixes and Apple’s release notes for the current version.
Quick answers
When was the Apple Watch SE 3 released?
Apple released the Apple Watch SE 3 in September 2025. Prices started at GBP 219 or USD 249.
Is the Apple Watch SE 3 waterproof?
SE 3 is water resistant to 50m.
Does the Apple Watch SE 3 have ECG?
No, SE 3 has no ECG and no blood oxygen sensor. It does have a wrist temperature sensor, which enables cycle tracking with retrospective ovulation estimates and a Sleep Score.
What sizes does the Apple Watch SE 3 come in?
SE 3 comes in 40mm and 44mm aluminium cases, both 10.7mm thick. The 40mm weighs 26.3 to 26.4g and the 44mm weighs 32.9 to 33.0g.
What is the Apple Watch SE 3 battery life?
Apple claims up to 18 hours of normal use, unchanged from SE 2, and up to 32 hours in Low Power Mode. Fast charging reaches up to 80 per cent in about 45 minutes.
Does the Apple Watch SE 3 have cellular?
Yes, SE 3 is available with 5G and LTE connectivity, replacing the 4G LTE and UMTS of SE 2.
Further reading
- the5krunner: Apple Watch SE 3 v SE 2, worth the upgrade?
- the5krunner: Best Apple Watch 2026 buyer’s guide
- Apple specifications index
Small things I always use
- Garmin 90-degree charging adapter: Charges your Garmin with any USB-C cable. Essential when travelling. I use one.
- Body Glide: The blue anti-chafing stick swimmers and runners carry. I use it.
- Speedo earplugs: Fewer ear infections and no cold-water dizziness. I use them.
- Dryrobe Advance: My winter changing robe for open-water swims. I use one. A cheaper option is the AONYIYI changing robe.
- Maurten: Race fuel that stays easy on the stomach. I use them.
- Beet It Sport nitrate shots: Beetroot shots I take in the days before a race. I use them.
- Garmin charging puck: The quickest way to top up before a session. I use one.
- Injinji: Toe socks that stop rubbing, so you run more. I use them.
- Ultimate toe protectors: Stop black toenails on long runs. They work. I use them.
- Compressport R2 v2 calf sleeves: My calf sleeves of choice. I use them.
- Cellucor C4: My pre-workout before hard sessions.
- TPU tubes: Schwalbe Aerothan, Tubolito and Pirelli SmarTube. Light, tiny spares. I use all three.
- G8 insoles: Adjustable arches, perfect position. I use them.
- Cycplus Cube: A 97g electric pump that gets a road tyre rideable in two minutes. I carry one. 5% off with code THE5KRUNNER.
Health, recovery and sleep
- Kineon MOVE+: Red and infrared light for sore knees, Achilles and other joints after hard training. I use it.
- FreeStyle Libre 3 Plus: Shows how my blood sugar responds to diet. Occasional use.
- hDrop: Measures my sweat loss in summer and indoors. I use it.
- Fourth Frontier Zone: Checks my heart under load in hard sessions.
- Oura Ring 5: My partner’s recovery tracker of choice.
- Eight Sleep: A cooling mattress cover my partner and I use nightly.
Watches and sensors
- Polar H10: My daily driver for waking HRV.
- Polar Verity Sense: My backup arm-worn HR sensor.
- Nomad bedside charger: Charges my iPhone and Apple Watch overnight. I use it, and many of their bands.
- Train.Red: The best muscle oxygen sensor I’ve used. Occasional use.
- Tymewear: Accurate heart rate and reliable ventilatory zones. I use it to pace endurance rides over an hour.
- Garmin Forerunner 970: A pro-grade triathlon watch. I use this.
- Apple Watch Ultra 4: My daily smartwatch. No phone needed on rides.
On the bike
- Continental GP5000 for everyday riding, and Aero 111 on the front for special occasions. I use both.
- Helmets: Specialized S-Works Evade 3 for road riding, and Rudy Project Wing for TT-style races. I use both.
- Ravemen FR300: A front light that mounts under your Garmin or Wahoo. I use one.
- Ravemen FR1000: The light and the computer mount in one unit, so nothing else goes on the bars. Better than mine.
- Ravemen FR1500SE: 1,500 lumens hanging under your Garmin, for proper night rides.
- Ravemen FR1100SE: 1,100 lumens under your Garmin, and up to 46 hours on slow flash.
- Ravemen FR500: A brighter FR300 with the same mount.
- Wahoo TRACKR Radar: I use it on one bike and Varia on the other. They perform the same.
- Garmin Varia RTL515: Radar that warns you of cars from behind. I use this model.
- Wahoo ELEMNT Roam 3: The bike computer that’s easy to use. I use mine on most rides.
- Favero Assioma Pro RS2: Accurate power pedals that swap easily between bikes. I use this model.
Home and indoor training
- NPE Runn: Makes my basic treadmill smart, sending more accurate speed and distance to my watch and Zwift. I use it.
- Google Wifi: Keeps Zwift connected in my pain cave. I use it.
- Apple TV 4K: Zwift on the big screen. I use two.
- Google Nest Doorbell (wired, 2nd gen): My video doorbell, running in both Google Home and Apple Home via Starling. I use it.
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