Apple Watch Series 12 vs Apple Watch SE 3
The Apple Watch Series 12 lists for about $150 more than the Apple Watch SE 3. On the headline smartwatch-mode figure, 24 h for the Apple Watch Series 12 against 18 h for the Apple Watch SE 3. For a GPS workout the figures are 10 h and 7 h. Every other published figure for both is in the table, with the rows where they differ tinted.
Apple
Apple Watch Series 12
~$399
Apple's 2026 mainstream watch adds a new Health Sensing System that, per Apple, takes background heart rate readings 60x more often than Series 11 and HRV 24x more often, feeding a new Readiness score.
Best for: iPhone owners who want the full Apple health suite and don't need multi-day battery
Apple
Apple Watch SE 3
~$249
Launched in 2025 and still Apple's entry model, the SE 3 has an always-on display, a temperature sensor with sleep score, and 5G on cellular versions.
Best for: First-time iPhone watch buyers, or a child's watch set up through Apple Watch For Your Kids
| Specification | Apple Watch Series 12 | Apple Watch SE 3 |
|---|---|---|
| Approx. price | ~$399 (42mm aluminum GPS, 'From $399' on apple.com/shop/buy-watch) | ~$249 (40mm aluminum GPS, 'From $249' on apple.com/shop/buy-watch) |
| Type | Everyday smartwatch | Everyday smartwatch |
| Platform | watchOS | watchOS |
| Case sizes | 42 mm / 46 mm | 40 mm / 44 mm |
| Weight | 42 mm: 32.2 g · 46 mm: 39.5 g (aluminum, GPS, case only (Apple spec page)) | 40 mm: 26.3 g · 44 mm: 32.9 g (aluminum, GPS, case only (Apple spec page)) |
| Battery, smartwatch mode | 24 h (Apple: 'All-day battery life, up to 24 hours of normal use' (both sizes; includes 6 hours of sleep tracking)) | 18 h (Apple: 'All-day battery life, up to 18 hours of normal use' (both sizes)) |
| Battery, always-on display | Not published by the maker | Not published by the maker |
| Battery, GPS workout | 10 h (Apple: 'Up to 10 hours workout tracking' — outdoor run, without iPhone, heart rate on (single-frequency L1 GPS)) | 7 h (Apple: 'Up to 7 hours workout tracking' — outdoor run, without iPhone, heart rate on (L1 GPS)) |
| Battery note | Apple: up to 38 hours in Low Power Mode; Apple does not state whether the always-on display was enabled in its 24-hour test | Apple: up to 32 hours in Low Power Mode (including 6 hours of sleep tracking); 18-hour figure excludes sleep tracking |
| Works with | iPhone only | iPhone only |
| iPhone | Yes | Yes |
| Android | No | No |
| Phone limits | Needs iPhone 11 or later with iOS 27 or later; Apple sells no Android pairing | Needs iPhone 11 or later with iOS 27 or later; Apple sells no Android pairing |
| Paid tier | Apple Fitness+, $79.99/year | Apple Fitness+, $79.99/year |
| What the paid tier gates | No watch feature requires it; it adds guided workout and meditation video classes that use the watch's metrics on screen | No watch feature requires it; it adds guided workout and meditation video classes that use the watch's metrics on screen |
| Update years | Not published by the maker | Not published by the maker |
| Cleared health features | ECG app (FDA), Irregular rhythm notifications (FDA), Sleep apnea notifications (FDA), Hypertension notifications (FDA) | Irregular rhythm notifications (FDA), Sleep apnea notifications (FDA) |
| Display | OLED | OLED |
| Always-on display | Yes | Yes |
| Dual-band GPS | No | No |
| Maps | Downloadable maps, no topo (Apple: 'Offline maps with custom route creation' plus 'Topographic maps for thousands of national and regional parks (U.S. only)' — not worldwide topo) | Downloadable maps, no topo (Apple: 'Offline maps with custom route creation' plus 'Topographic maps for thousands of national and regional parks (U.S. only)' — not worldwide topo) |
| Music on the watch | Yes | Yes |
| LTE | Optional (GPS + Cellular version needs a carrier plan; the carrier sets the price (apple.com/watch/cellular)) | Optional (GPS + Cellular version needs a carrier plan; the carrier sets the price (apple.com/watch/cellular)) |
| Contactless pay | Yes | Yes |
| Flashlight | No | No |
| Water rating | 50 m (ISO 22810:2010) + IP6X | 50 m (ISO 22810:2010) |
| Case | aluminum | aluminum |
| Released | 2026 | 2025 |
Apple Watch Series 12: what it gives up
- Apple's 24-hour rating is half the Ultra 4's, so it is the one to pick only if charging every day or two suits you
- Single-frequency GPS only, where the Ultra 4 has dual-frequency
- Works only with an iPhone
- 10-hour workout figure is short for marathon-plus events
Apple Watch SE 3: what it gives up
- 18-hour rating is the shortest here; overnight sleep tracking needs Low Power Mode or a top-up
- No ECG app, hypertension notifications or blood oxygen, which Series 12 has
- 7-hour workout figure rules out long races
- Older S10 chip misses the Audio Intelligence features of Series 12
Full pages: Apple Watch Series 12 · Apple Watch SE 3