Comparison · Fitness watches · Desk research
Apple Watch SE (2nd generation) vs Apple Watch Ultra 4
Quick Answer
Apple Watch SE (2nd generation, 2022) is a 40mm or 44mm aluminum watch with the S8 SiP, a 2-core Neural Engine, 32GB, an LTPO OLED that is not Always-On, 1000 nits, 324×394 / 368×448, L1 GPS, 50m water resistance, Crash Detection, and Fall Detection. Apple Support lists up to 18 hours of battery and about 80% charge in 1.5 hours. It does not list ECG, Blood Oxygen, or temperature sensing — Apple’s ECG footnote excludes SE models. Ultra 4 (9.
The verdict
Apple Watch SE (2nd generation) or Apple Watch Ultra 4 — quote the two manufacturer sheets.
Why: SE 2 is the 2022 aluminum 40/44mm watch with S8, 32GB, a non-Always-On LTPO OLED at 1000 nits, L1 GPS, 50m, Crash/Fall Detection, and no ECG, no Blood Oxygen, and no temperature sensing on Support 111853. It is not named on Apple’s watchOS 27 list. Ultra 4 is the current 49mm adventure SKU on that list. Quote Apple’s list; this page does not invent an end-of-support date.
Buy Apple Watch SE (2nd generation) if
You already wear SE (2nd generation), you do not need ECG, Blood Oxygen, Always-On, or watchOS 27, and Crash/Fall Detection plus 50m swimproof still cover what you do.
Buy Apple Watch Ultra 4 if
You want Apple’s current 49mm adventure watch: Grade 5 titanium, Action Button, dual-frequency GPS, satellite SOS/Messages/Find My, ECG, Health Sensing System, and Apple’s 50-hour normal-use / 45-hour Max Extended Workout claims.
Spec comparison
OEM rows only. SE (2nd generation) numbers are from Apple Support 111853. Ultra 4 numbers are from apple.com/apple-watch-ultra-4/specs/. Cells Apple does not publish stay marked.
| Spec | SE (2nd generation) | Ultra 4 |
|---|---|---|
| Year introduced | 2022 (Support) | 2026 (Newsroom 9 September 2026) |
| Case size(s) | 40mm and 44mm | 49mm only |
| Case material | Aluminum | Grade 5 titanium |
| Dimensions (44mm / 49mm) | 44 × 38 × 10.7mm | 49 × 44 × 12mm |
| Display | Retina LTPO OLED (Always-On not listed); 40mm 324×394; 44mm 368×448; 326 ppi; up to 1000 nits | Always-On LTPO3; 422×514; 326 ppi; 3,000 nits peak; 1 nit minimum |
| Front crystal | Ion-X | Flat sapphire |
| Chip / storage | S8 SiP, 64-bit dual-core; 2-core Neural Engine; 32GB | S11; 64GB |
| Battery — normal use | Up to 18 hours (Apple test, August 2022) | Up to 50 hours |
| Battery — Low Power / extra modes | Not listed on Support 111853 | Up to 84 hours Low Power; 18 hours outdoor; 25 hours Extended; 45 hours Max Extended Workout |
| Fast charge (OEM) | Up to 80% in about 1.5 hours | ~80% in about 45 minutes; 15 min ≈ 18 hours normal use |
| Weight (example SKUs) | GPS 44mm 32.9g; GPS 40mm 26.4g | 63.0g natural titanium; 63.1g black titanium (case only) |
| GNSS | L1 GPS, GNSS, Galileo, and QZSS | Precision dual-frequency GPS |
| Water | 50m (ISO 22810:2010); Apple: not scuba or high-velocity water | 100m (ISO 22810:2010); EN 13319 recreational dive to 40m |
| Dust | Not listed on Support 111853 | IP6X; MIL-STD-810H subsection list |
| Action Button / siren | Not listed | Action Button; siren Apple says is audible to 180m / 600 feet |
| Satellite | Not listed | Emergency SOS, Messages, Find My via satellite |
| Heart rate | Second-generation optical heart sensor | Health Sensing System |
| ECG | Not listed; Apple ECG footnote excludes SE models | ECG app (Series 4+, excluding SE) |
| Blood Oxygen | Not listed | Blood Oxygen app (region limits) |
| Temperature | Not listed | Temperature sensor (Apple: Series 8 or later, SE 3, Ultra models) |
| Safety | Emergency SOS, Crash Detection, Fall Detection | Same class plus satellite radios, siren, flashlight |
| OS / phone | Support lists iPhone Xs or later, including iPhone SE (2nd generation or later), with iOS 18 or later | watchOS 27; iPhone 11 or later / SE 2+, iOS 27 |
| watchOS 27 (Apple list) | Not named (list names SE 3, not SE 2) | On the list (Ultra 2 or later) |
| US start (dated) | Discontinued; no street price treated as fact | $799 (Newsroom, 9 September 2026) |
Who each watch is for
SE (2nd generation) is Apple’s 2022 value Watch: S8, Crash/Fall Detection, L1 GPS, 50m swimproof, no Always-On, no ECG, no Blood Oxygen, no temperature sensing on the Support page. If those holes are acceptable on a watch you already own, this page does not invent a scare headline.
Ultra 4 is the current adventure Apple Watch. The comparison is case class, Always-On, ECG / Blood Oxygen / Health Sensing System, dual-frequency GNSS, satellite, dive path, and Apple’s watchOS 27 named list (SE 3, not SE 2).
watchOS 27 — quote Apple
Series 12 Newsroom, 9 September 2026: “watchOS 27 will be available for Apple Watch Series 9 or later, Apple Watch SE 3, and Apple Watch Ultra 2 or later … and requires iPhone 11 or later or iPhone SE (2nd generation or later) with iOS 27 or later.” SE 3 is on that sentence. SE (2nd generation) is not.
ECG, Blood Oxygen, and temperature
Apple’s Ultra 4 spec-sheet footnote: the ECG app is available on Series 4 and later, excluding Apple Watch SE models. Support 111853 does not list Blood Oxygen or temperature sensors. Ultra 4 lists ECG, Blood Oxygen, and the Health Sensing System. Do not write ECG onto SE 2.
Battery
Copy Apple’s mode names. SE 2: up to 18 hours; up to 80% in about 1.5 hours (August 2022 tests). Ultra 4: 50 / 84 / 18 / 25 / 45 hours; 15 minutes → up to 18 hours. Max Extended Workout is outdoor run/walk/hike with GPS every second.
GNSS, water, and satellite
SE 2 is L1 GNSS and 50m swimproof. Ultra 4 is dual-frequency GNSS, 100m / 40m dive, Action Button, and satellite. Do not upgrade SE 2 to “Ultra GPS” in prose.
Price
$799 is Apple’s published US starting price for Ultra 4 on 9 September 2026. SE (2nd generation) is discontinued; this page does not treat a refurb ticket as a fact.
Frequently asked questions
Does Apple Watch SE (2nd generation) get watchOS 27?
Apple’s Series 12 Newsroom (9 September 2026) says watchOS 27 will be available for Apple Watch Series 9 or later, Apple Watch SE 3, and Apple Watch Ultra 2 or later, and requires iPhone 11 or later or iPhone SE (2nd generation or later) with iOS 27 or later. SE 3 is named. SE (2nd generation) is not. This page quotes Apple.
Does SE 2 have ECG?
No. Support 111853 lists a second-generation optical heart sensor and does not list an electrical heart sensor or ECG app. Apple’s Ultra 4 spec-sheet footnote: the ECG app is available on Series 4 and later, excluding Apple Watch SE models.
Does SE 2 have Blood Oxygen or temperature sensing?
No. Those sensors are not on Support 111853. Apple’s temperature footnote on Ultra 4 specs names Series 8 or later, SE 3, and Ultra models — not SE (2nd generation).
Is SE 2 Always-On?
No. Support 111853 lists a Retina LTPO OLED display at up to 1000 nits and 326 ppi. Always-On is not on that spec sheet. Ultra 4 lists Always-On LTPO3.
What are the SE 2 battery and charge claims?
Support 111853: up to 18 hours of normal use (August 2022 Apple tests); up to 80% charge in about 1.5 hours with the included Magnetic Charger to USB-C Cable. Ultra 4: up to 50 hours normal, 84 hours Low Power, 15 minutes ≈ 18 hours.