Apple Watch SE 3 survived September 9 unchanged and unrepriced, and it is now the only Apple Watch under $399. Apple lists it at From $249 with the S10 chip, 40mm and 44mm aluminum cases, up to 18 hours of battery and a 1000-nit Always-On display.
It is also the only watch Apple sells without an electrical heart sensor or a blood oxygen sensor, which is the single most important thing to know before spending $249 rather than $399. Apple’s own comparison grid muddies that point, and its tech specs page settles it.
What $249 buys
| Item | Apple Watch SE 3 |
|---|---|
| Published price | From $249 |
| Case sizes | 40mm and 44mm aluminum, Starlight or Midnight |
| Chip and storage | S10, 64-bit dual-core, 64GB |
| Display | Always-On, up to 1000 nits |
| Battery | Up to 18 hours, up to 32 hours in Low Power Mode |
| Water | 50 meters, swimproof |
| watchOS 27 | Supported, free on Monday, September 14 |
The launch price has not moved since the SE 3 arrived in September 2025 at $249, and Apple relisted it at From $249 after the watch briefly went unavailable in the days before the September 9 event.
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The two sensors Apple leaves out
Apple’s SE 3 tech specs page lists a temperature sensor, a compass, an always-on altimeter, a high-g accelerometer, a gyroscope and an ambient light sensor. It does not list an electrical heart sensor, and it does not list a blood oxygen sensor.
Apple’s Watch comparison page disagrees, marking ECG and Blood Oxygen as present in the SE 3 column. Treat that as unreliable rather than good news. Apple’s own ECG availability wording describes the app as available on “Apple Watch Series 4 and later (excluding Apple Watch SE models) and all Apple Watch Ultra models”, which excludes the SE 3 by name.
That is the real line between $249 and $399. The Series 12 Health Sensing System reads heart rate every five seconds and adds ECG, Blood Oxygen, a depth gauge to 6 meters and a water temperature sensor, none of which the SE 3 offers.
Battery, brightness and the glass
The SE 3 is rated at up to 18 hours of normal use, the figure Apple used for four generations of Apple Watch, and up to 32 hours in Low Power Mode. Apple quotes 80 percent charge in about 45 minutes, and its compare page adds 15 minutes for up to 8 hours of normal use.
The display peaks at 1000 nits, half the Series 12 figure and a third of the 3000 nits on Ultra 4. The front is Ion-X glass, which Apple describes as having four times the crack resistance of the previous SE, rather than the Ceramic Shield 2 crystal on Series 12 aluminum models.
| Specification | Apple’s published figure |
|---|---|
| 40mm case | 40 x 34 x 10.7 mm, 26.3 g GPS, 26.4 g cellular |
| 44mm case | 44 x 38 x 10.7 mm, 32.9 g GPS, 33.0 g cellular |
| Fast charge | 80 percent in about 45 minutes |
| Peak brightness | 1000 nits, Always-On |
| 44mm price | Not published, only From $249 |
| Cellular price | Not published |
What it still gets on Monday
The SE 3 is on Apple’s watchOS 27 list alongside Series 9, 10, 11 and 12 and Ultra 2, 3 and 4, so it receives Monday’s free update. Apple also includes SE 3 in its Apple Intelligence device list when it is paired with a compatible iPhone, and names it among the models that support sleep apnea notifications.
- Siri AI on the wrist, in beta, English first, with French, Japanese, Korean, Portuguese and Spanish in October.
- The dynamic app grid, the single-handed tap gesture for the Smart Stack and the Siri Modular watch face.
- Perimenopause and menopause support in Cycle Tracking, for users 40 and over, not in all regions.
- Workout Buddy without a nearby iPhone, over Wi-Fi or cellular, now including Spanish.
- A requirement Apple sets for every supported watch: iPhone 11 or later, or iPhone SE (2nd generation or later), running iOS 27.
What Apple has tied to the new S11 chip does not come to the SE 3. Audio Intelligence, the Readiness app and the new Health Sensing System were all announced with Series 12 and Ultra 4, as covered in our event recap.
What has not been confirmed
Apple publishes no SE 3 price beyond From $249, so the 44mm and cellular figures are unknown from Apple’s own pages. It has not published a wrist size range for the SE 3, an Apple Upgrade lease figure for it, band prices, a trade-in value for any Apple Watch model, or a repair price. Apple has also not said whether the Readiness app appears on watches older than Series 12.
watchOS 27 lands on Monday, September 14 and costs nothing on an SE 3 you already own. If you are buying, Series 12 and Ultra 4 reach stores on Friday, September 18, which is the first day the three watches can be compared on a shelf rather than on a grid.
