Apple’s compare page now covers five Apple Watch models that all run watchOS 27: Apple Watch SE 3 from $249, Apple Watch Series 12 from $399, Apple Watch Ultra 4 from $799, and last year’s Series 11 and Ultra 3. For most buyers Series 12 is the answer, because it is the cheapest watch with the S11 chip and the new Health Sensing System; Ultra 4 is for anyone who needs 50 hours of battery, 100 m water resistance or satellite messaging.
Series 11 and Ultra 3 keep the S10 chip and the older sensors, and SE 3 has a dimmer display and a shorter battery. The table uses Apple’s compare page and tech specs.
Key facts: five Apple Watches side by side
| Spec | SE 3 | Series 11 | Series 12 | Ultra 3 | Ultra 4 |
|---|---|---|---|---|---|
| Price | From $249 | $399 at launch (2025) | From $399 | $799 at launch (2025) | From $799 |
| Chip | S10 | S10 | S11 | S10 | S11 |
| Case sizes | 40, 44 mm | 42, 46 mm | 42, 46 mm | 49 mm | 49 mm |
| Materials | Aluminum | Aluminum, titanium | Aluminum, titanium, ceramic | Titanium | Titanium |
| Peak brightness | 1000 nits | 2000 nits | 2000 nits | 3000 nits | 3000 nits |
| Battery (normal / Low Power) | 18 h / 32 h | 24 h / 38 h | 24 h / 38 h | 42 h / 72 h | 50 h / 84 h |
| Fast charge to 80% | About 45 min | About 30 min | About 30 min | About 45 min | About 45 min |
| Water resistance | 50 m | 50 m | 50 m | 100 m | 100 m |
| Satellite | No | No | No | Yes | Yes |
All five have 64GB of storage, 5G on cellular models, Wi-Fi 4 and Bluetooth 5.3. The Series 11 and Ultra 3 prices come from Apple’s September 2025 press releases; Apple’s Store page lists “From” prices only for SE 3, Series 12 and Ultra 4.
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What Series 12 and Ultra 4 add over Series 11 and Ultra 3
The S11 chip is the dividing line. Apple’s Series 12 page says the Health Sensing System takes background heart rate readings 60 times more often than Series 11 and HRV readings 24 times more often: heart rate every five seconds, HRV as often as every five minutes. The Ultra 4 page makes the same 60x and 24x claims against Ultra 3.
Those readings feed the new Readiness app, a daily 0 to 10 score with four recommendations: Recover, Pace Yourself, Ready, Go For It. Apple also ties Live Rewind and Siri Recap to the S11 chip and its Secure Exclave, and its Series 12 page lists Sound Recognition as coming late 2026.
Aluminum Series 12 models get a Ceramic Shield 2 front crystal, 60 percent tougher than the Ion-X glass on aluminum Series 11 by Apple’s measure, and Series 12 adds ceramic cases in Pearl White and Night Blue. Ultra 4 moves from 42 to 50 hours of normal use and from 72 to 84 in Low Power Mode, and a 15-minute charge gives 18 hours instead of 12, for 1.4 g more weight.
Apple Watch SE 3: what $249 leaves out
Apple Watch SE 3 is the only current watch with a 1000-nit display, and Apple rates it at 18 hours of normal use and 32 in Low Power Mode, against 24 and 38 for Series 12. It comes in 40 mm and 44 mm aluminum in Starlight and Midnight, weighs 26.3 g or 32.9 g, and charges to 80 percent in about 45 minutes.
Apple’s SE 3 tech specs list no electrical heart sensor, no Blood Oxygen sensor and no temperature sensor, so ECG, Blood Oxygen and wrist temperature in Cycle Tracking are Series and Ultra features. For a first watch or a child’s watch, that trade for $150 less is reasonable; for health tracking, it is not.
Who should buy which Apple Watch
- Series 12: the default. Same $399 start as last year, the new sensors, Ceramic Shield 2 on aluminum, 10-hour outdoor workouts and 12 hours from a 15-minute charge. Apple Upgrade lease from $11.99 a month.
- Ultra 4: for hikers, divers, ultrarunners and anyone two days from a charger. 100 m water resistance, EN13319 scuba to 40 m, dual-frequency GPS, satellite, and 45 hours in Max Extended workout mode. $24.99 a month on Apple Upgrade.
- SE 3: the budget watch. Fine for notifications, workouts and Apple Pay, but no ECG, no Blood Oxygen and the shortest battery.
- Series 11: only at a clear discount. Same display, battery and water rating as Series 12, but the S10, older sensors and Ion-X glass.
- Ultra 3: the same logic. Satellite, 100 m and 3000 nits, but 42 hours and no Health Sensing System.
watchOS 27 runs on all five
Apple’s watchOS page lists SE 3, Series 9, 10, 11 and 12, and Ultra 2, 3 and 4 as compatible, so none of these watches is stranded on software. It is a free update on Monday, September 14, the same day as iOS 27, and needs an iPhone 11 or later on iOS 27. What the older watches do not get is anything that depends on the S11: five-second heart rate readings, the Readiness score, Live Rewind and Siri Recap.
What Apple has not said
- Whether Series 11 and Ultra 3 remain on sale from Apple, and at what price.
- Per-configuration prices for Series 12 titanium, ceramic and cellular models, or for Ultra 4 beyond the $799 start.
- Display sizes in inches, band prices, and trade-in values for older watches.
- A date for Sound Recognition beyond “coming late 2026”.
Series 12 and Ultra 4 are on pre-order now and reach stores on Friday, September 18, in the US, UK, Canada, Australia, India, Japan and more than 50 other countries. SE 3 is listed from $249 on Apple’s Store page. For everything else Apple announced, see our event recap.
