Buy the SE 3. A used first-gen Ultra costs about the same, but Apple left it off watchOS 27. I've worn one for 10 months. Pay for the Ultra only for its looks, ECG or diving.
Buy the Apple Watch SE 3. A used first-generation Ultra costs about the same as a new SE 3 with cellular, and the SE 3 runs watchOS 27 while the Ultra stays on watchOS 26.
I’ve worn a used Ultra 1 every day for 10 months, and I still like it. Buy one only if you want its titanium look, the ECG and Blood Oxygen apps, a dive-rated case or a brighter screen, and you don’t care about new software. The SE 3 is wrong for you if you need an ECG or plan to scuba dive with your watch.
How I know
I bought my Apple Watch Ultra (1st generation) used in November 2025 for about $355 and have worn it all day since. It scored a 6. Before it I wore the first Apple Watch SE. I have not worn the SE 3.
The SE 3 side comes from Apple’s US pages, all checked on November 13, 2026: the SE 3 tech specs, the SE 3 product page, the Apple Store buy page for prices, and the watchOS page for which watches get watchOS 27. The Ultra’s rated specs come from Apple’s Ultra tech specs. How a product earns a score here is on how I test.
The two side by side
| Apple Watch Ultra (1st gen), used | Apple Watch SE 3 | |
|---|---|---|
| Price | $250 to $325 used or refurbished on eBay (late October 2026, from my review) | $249 (40mm GPS), $279 (44mm GPS), $299 (40mm cellular), $329 (44mm cellular) at Apple, Nov 13, 2026 |
| Software | watchOS 26, security updates only | watchOS 27 |
| Chip | S8 | S10 |
| Case | 49mm titanium, cellular built in | 40mm or 44mm aluminum |
| Weight (Apple) | 61.3 g | 26.3 g to 33.0 g |
| Display (Apple) | Always-on, up to 2,000 nits | Always-on, up to 1,000 nits |
| Battery (Apple) | Up to 36 hours, 60 in Low Power Mode | Up to 18 hours, 32 in Low Power Mode |
| Battery in my use | Two top-ups a day at 88% battery health | Not tested |
| ECG and Blood Oxygen apps | Yes | Not listed in Apple’s SE 3 specs |
| Sleep features | Sleep stages and a sleep score on watchOS 26 | Sleep stages, sleep score and sleep apnea notifications (Apple) |
| Water | 100 m, dive-rated to 40 m | 50 m, swimproof, not for scuba |
| Tested here | Yes, 10 months, score 6 | No |
The difference that decides it: software
When I bought my Ultra, it was fully up to date, and a used one felt like a smart way in. On September 14 Apple shipped watchOS 27, and my watch didn’t get it. Apple’s watchOS page lists the SE 3, Series 9 and newer, and Ultra 2 and newer. The first Ultra isn’t on the list.
Nothing broke on mine. Apple Pay, the stopwatch, heart rate and Mac unlocking work the same as they did before the update. What you give up is everything new: Siri AI, the new tap gesture and the health features that arrive in later releases. Apple says the first Ultra keeps getting security updates, but it hasn’t said for how long.
The SE 3 gets all of that. Apple lists Siri AI on it in beta, along with double tap and wrist flick gestures. Siri AI also needs an iPhone that supports Apple Intelligence.
At the same price, I’d rather have the watch Apple is still building for. That’s the answer for me, and I’m the one wearing the Ultra.
What the Ultra still does better
It looks better. That’s the main reason I wear it. The titanium case with a metal band is the best-looking watch I’ve owned.
It has more health sensors. Apple’s Ultra specs list an electrical heart sensor for the ECG app and a blood oxygen sensor. Apple’s SE 3 spec page lists neither, and Apple’s own footnote says the ECG app isn’t available on any Apple Watch SE.
It’s built for water and the outdoors. Apple rates the Ultra to 100 meters and for recreational scuba diving to 40 meters, with a depth gauge and an 86-decibel siren. The SE 3 is rated to 50 meters for swimming only.
Its rated battery is twice as long. Apple says 36 hours against 18 for the SE 3. In my use, the age of a used unit eats into that. Mine shows 88% battery health and needs a charge during my shower and another before bed. Any used Ultra you buy is three to four years old, so check its battery health before you pay.
What the SE 3 does better, on paper
It’s half the weight. Apple lists 33 grams for the 44mm cellular SE 3 and 61.3 grams for the Ultra case. My Ultra is a big watch, and some nights it gets in the way in bed.
It adds sleep apnea notifications. Apple’s SE 3 spec page lists them alongside sleep stages and a sleep score; the Ultra’s spec page doesn’t. My Ultra’s sleep tracking gets my nights wrong in both directions, and my old first-generation SE tracked sleep better. I can’t tell you whether the SE 3 is accurate, because I haven’t worn one.
It charges fast. Apple says 15 minutes gives up to 8 hours of normal use, and 8 minutes covers up to 8 hours of sleep tracking.
It’s new. You buy it from Apple, with a fresh battery, instead of from a stranger.
Who should buy the used Ultra
Buy a used Ultra 1 if you want the Ultra look, Apple Pay, a stopwatch and heart rate on your wrist, and you don’t follow watchOS updates. Buy it if you dive, swim in open water or want the ECG app. At $250 to $325 it’s a bargain for that buyer.
Skip it if you care about software, run betas or want good sleep data. That’s me. If you want an Ultra that stays current, Apple’s refurbished Ultra 2 was $509 on November 13, and a refurbished Ultra 3 was $599. My full take on the 2026 lineup is in which Apple Watch to buy.
My recommendation
Buy the SE 3. Get the 44mm with cellular for $329 if you want to compare it with a used Ultra, since every Ultra has cellular. Get the $249 40mm GPS model if you only want Apple Pay, notifications and Mac unlocking. Buy a used Ultra 1 only for the look, the ECG or diving, and accept that its software is frozen.
If you mostly want sleep data, neither watch is the cheapest route. A ring is easier to wear in bed: see Colmi R09 vs R02 and my sleep tracker guide.
FAQ
Is the Apple Watch Ultra 1 still worth buying in 2026?
Only if you don’t care about new software. Apple left it off watchOS 27, so it gets security updates and no new features. At $250 to $325 used, it’s a bargain for the look, Apple Pay and heart rate. For current software at the same money, the SE 3 is the better buy.
Does the Apple Watch Ultra 1 get watchOS 27?
No. Apple’s watchOS page lists the SE 3, Series 9 to 12, and Ultra 2 to 4. The first Ultra stays on watchOS 26. Mine runs watchOS 26.6, and every feature I used before still works.
Does the Apple Watch SE 3 have an ECG?
No. Apple’s footnote says the ECG app isn’t available on Apple Watch SE, and the SE 3 spec page lists no electrical heart sensor. The first Ultra has one.
Which has better battery life, the Ultra 1 or the SE 3?
On Apple’s ratings, the Ultra: up to 36 hours against 18 for the SE 3. A used Ultra’s battery has aged, though. Mine is at 88% health and needs two short charges a day.
Is the SE 3 better for sleep tracking than the Ultra 1?
It’s half the weight and adds sleep apnea notifications, according to Apple’s spec page. I haven’t worn an SE 3, so I can’t speak to its accuracy. My Ultra logs my sleep wrong in both directions, and it’s heavy in bed.