Apple sells exactly three Apple Watch lines right now, and the naming does you no favours. SE 3 sounds like a third-generation budget model (it is). Series 12 sounds like the twelfth of something (also true). Ultra 4 sounds expensive. That one’s right too.
Here’s the thing most comparison charts skip: the gap between them isn’t really about the chip. It’s battery, brightness, a couple of health sensors, and how rough you plan to be with it. So this page lines the three up on the stuff that changes your day, then tells you who each one is for.
The short version
- SE 3 is the one to buy if you want calls, texts, notifications, fitness and sleep tracking, and you don’t need an ECG or blood oxygen readings. It starts at $249 (GPS) or $299 (GPS + Cellular).
- Series 12 adds the full set of heart sensors, a brighter wide-angle display, dust resistance and a 6m depth gauge. From $399 (GPS) or $499 (GPS + Cellular).
- Ultra 4 is the outdoors and endurance watch: up to 50 hours of battery, a 49mm titanium case, 100m water resistance, a siren and satellite features. It only comes as GPS + Cellular, from $799.
Apple Watch comparison chart
| Feature | SE 3 | Series 12 | Ultra 4 |
|---|---|---|---|
| Starting price, GPS | $249 | $399 | Not sold as GPS only |
| Starting price, GPS + Cellular | $299 | $499 | $799 |
| Case sizes | 40mm or 44mm | 42mm or 46mm | 49mm |
| Case material | Aluminum | Aluminum, titanium or ceramic | Titanium |
| Display | Always-On, up to 1000 nits | Always-On wide-angle OLED, up to 2000 nits | Always-On wide-angle OLED, up to 3000 nits |
| Chip | S10 | S11 | S11 |
| Battery, normal use | Up to 18 hours | Up to 24 hours | Up to 50 hours |
| Battery, Low Power Mode | Up to 32 hours | Up to 38 hours | Up to 84 hours |
| Fast charge to 80% | About 45 minutes | About 30 minutes | About 45 minutes |
| ECG app | No | Yes | Yes |
| Blood Oxygen app | No | Yes | Yes |
| Sleep apnea notifications | Yes | Yes | Yes |
| Fall and Crash Detection | Yes | Yes | Yes |
| Water resistance | 50m (swimming) | 50m, depth gauge to 6m | 100m, depth gauge to 40m |
| Dust resistance | Not rated | IP6X | IP6X |
| GPS | GPS | Precision L1 GPS | Precision dual-frequency (L1 + L5) |
| Satellite features | No | No | Emergency SOS, Messages and Find My via satellite |
| Siren | No | No | Yes |
SE 3: the sensible pick for most people
The SE 3 does the everyday Apple Watch job well. Notifications, calls, texts, Apple Pay, workouts, sleep tracking with a sleep score, sleep apnea notifications, Fall Detection and Crash Detection are all there. It has an Always-On display too, so you can glance at the time without lifting your wrist.
What you give up is mostly health hardware: no ECG app and no Blood Oxygen app. The screen tops out at 1000 nits, battery is rated at up to 18 hours, and there’s no dust rating. For a first watch, a kid’s watch or a parent who mainly wants calls and Fall Detection, that trade is easy to live with. If that’s your plan, our guide to setting up an Apple Watch for your kids walks through the setup.
Series 12: the full feature set in a normal-sized watch
Series 12 is where the heart sensors arrive: the ECG app, the Blood Oxygen app and hypertension notifications. The display is twice as bright as the SE 3’s at its peak, you get a choice of aluminum, titanium or ceramic, and charging is quicker (about 30 minutes to 80%).
Battery is rated at up to 24 hours, or up to 38 in Low Power Mode. Fine for a day and a night of sleep tracking, but you’ll be charging most days. Honestly, this is the one to get if health data matters to you and you don’t want a big, chunky case.
Ultra 4: for long days, water and the outdoors
The Ultra 4 is a different animal. Its 49mm titanium case is the largest, its display is the brightest at up to 3000 nits, and its battery is rated at up to 50 hours (84 in Low Power Mode). It’s rated for 100m of water resistance with a depth gauge to 40m, and it adds a siren plus satellite features for when there’s no cell signal at all.
It only comes as GPS + Cellular, so every Ultra 4 can take a cellular plan. The catch is the size and the price. If you’re not hiking, diving or running ultras, the Series 12 does most of the same everyday work for less.
GPS or GPS + Cellular?
On the SE 3 the cellular version costs $50 more at Apple’s starting prices; on the Series 12 it’s $100 more. Cellular lets the watch call, text and stream without your iPhone nearby, but it also needs its own line. Our guide to Apple Watch cellular vs GPS covers that choice in detail, and the Apple Watch cellular plan comparison lines up what each carrier charges for the line.
On US Mobile, a watch line is $6.50 a month with taxes and fees included and no activation fee, whether it shares your number or gets its own. If you’re ready to add one, see the US Mobile Apple Watch plan.
Already own an older model?
Older watches still do plenty. Whether yours can take a cellular line depends on the model and the carrier, so check before you buy a plan. For specific models we have:
- Apple Watch SE features
- Apple Watch SE 2 battery life
- Apple Watch Series 8 battery life
- Apple Watch Series 7 battery life
- Setting up Apple Watch Series 4 cellular
How we compared them
Every spec and price on this page comes from Apple’s own compare page, read on 18 October 2026. Prices are Apple’s starting prices before tax; retailers and carriers may charge differently. Battery figures are Apple’s rated numbers, not our own tests. US Mobile wrote this comparison, and the US Mobile plan price comes from US Mobile’s own plan page, checked 5 October 2026.
Frequently Asked Questions
What is the difference between Apple Watch SE and Series?
The Series 12 adds the ECG app, the Blood Oxygen app, a brighter wide-angle display (up to 2000 nits versus 1000), dust resistance, a 6m depth gauge and longer battery life (up to 24 hours versus 18). The SE 3 keeps calls, texts, fitness, sleep tracking and Fall Detection for a lower price.
How many Apple Watch models are there?
Apple currently sells three Apple Watch lines: the SE 3, the Series 12 and the Ultra 4. The SE 3 and Series 12 each come in two case sizes and in GPS or GPS + Cellular versions, while the Ultra 4 comes in one 49mm size and only as GPS + Cellular.
Which Apple Watch models have sleep apnea detection?
All three current models, the SE 3, Series 12 and Ultra 4, list sleep apnea notifications on Apple’s compare page, along with sleep tracking and a sleep score. Older models vary, so check Apple’s compare page for the exact watch you own before relying on it.
Which Apple Watch models have fall detection?
Every current Apple Watch, the SE 3, Series 12 and Ultra 4, includes Fall Detection and Crash Detection. On a GPS + Cellular model with an active line, the watch can call emergency services after a hard fall even when your iPhone isn’t with you.
What’s the difference between 40mm and 44mm Apple Watch?
On the SE 3, the 44mm case has a larger screen (977 square millimetres versus 759) and weighs a few grams more. Features, chip and rated battery life are the same in both sizes, so the choice comes down to your wrist and how much screen you want.
Which Apple Watch has the best battery life?
The Ultra 4, by a wide margin. Apple rates it at up to 50 hours of normal use and up to 84 hours in Low Power Mode, against up to 24 hours for the Series 12 and up to 18 hours for the SE 3.
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