Apple Watches are useful sidekicks for iPhones, serving up calls and notifications while also handling practical tasks like music control and timers. Plus they’re aces at tracking health and fitness metrics. While there are just three Apple Watch models, sussing out the differences between them can help you determine if the budget-friendly Apple Watch SE is enough, or if you’ll be better served by the high-end Ultra 2. Ultimately, we think the Series 9 is the best Apple Watch for most people, but this guide breaks down the details of all three models so you can decide which model is the best for you.
What to look for in an Apple Watch
Chips and sensors
Both the Series 9 and Ultra 2 were updated last September with Apple’s latest smartwatch silicon, the S9 SiP (system-in-package). In addition to on-device processing of Siri requests, the chip supports a new Double Tap gesture that lets you answer calls or stop an alarm by tapping your thumb and forefinger together twice. It also enables faster machine learning performance for interpreting sensor data, recognizing speech and performing other “thinking” tasks. The Apple Watch SE still relies on the S8 SiP, which was also used in the Series 8 and the original Ultra.
Both the Series 9 and Ultra 2 can take an ECG and have temperature sensors to help track ovulation. All three models have a compass, altimeter and support fall- and crash-detection. The Apple Watch Ultra 2 has an onboard SOS siren, as well as dive features like a depth gauge. The two higher-end models include sensors to measure blood oxygen, but a recent patent dispute has forced Apple to disable that feature on new models sold in the US.
Displays and case sizes
The Apple Watch 9 and the Ultra 2 have always-on displays, but you’ll have to lift your wrist to tell time or read notifications on the SE. The SE can reach a maximum brightness of 1,000 nits, the Series 9 can get as bright as 2,000 and the Ultra 2 hits 3,000 nits. Both the higher-end screens can dim to a single nit, making them less distracting in the dark. As for case sizes, the SE is available in 40 or 44mm and the Series 9 comes in 41 or 45mm. The Ultra 2 just comes in one case size measuring 49mm.
Since it’s the largest wearable, the Apple Watch Ultra 2 sports the biggest battery and can last for a claimed 36 hours on a charge. That number jumps up to 72 hours if you turn on low power mode. Both the Apple Watch 9 and the SE get 18 hours of life on a charge, and longer when using battery saver mode.
Believe it or not, all three Apple Watches have similar fitness chops. The Activity app uses three “rings” to keep tabs on how much you’re moving in a day: The Move ring tracks your active calories; the Exercise ring monitors the minutes you’ve spent walking, running, doing yoga and so on; and the Stand ring tells you how many hours in a day you’ve stood up and moved around for at least one minute.
Different internal sensors detect those activities, for example the accelerometer senses when you’re moving versus sitting still, and the optical heart rate sensor judges how hard you're working out and how many calories you’ve burned. You can set your goals for each ring and you’ll earn badges and animations when you hit them.
The Workout app lets you start and track an exercise session. The sensors can even auto-detect when you’re working out, tapping your wrist to suggest you track the activity. Apple Watches will integrate with Apple’s Fitness+ subscription, displaying real time heart rate and calorie burn data on your iPhone, iPad or even Apple TV 4K as you take a class. Fitness+ also includes audio-guided walks and runs with just your watch and Bluetooth earbuds. All three models support the Activity and Workout apps for free. The Fitness+ app also works with all Apple Watches, but costs $10 per month.
You can get the weather, start a workout, identify a song and dictate a text just by asking Siri. All Apple Watch models support the Raise to Speak feature that bypasses the need to say “Hey Siri” and will instead listen for your request when you lift your wrist near your mouth.
Both the Series 9 and the Ultra 2 utilize onboard processing of Siri requests. That means executing simple requests like starting workouts and timers are quicker, as they won’t need to access external networks. However, requests like sending texts or getting weather forecasts still need to communicate with Wi-Fi or cellular, so you’ll need to have your phone nearby if you have a GPS-only model.
There’s a $550 difference between the cheapest and most expensive Apple Watch. For $250, you can get the 40mm Apple Watch SE with GPS-only connectivity. The Apple Watch Series 9 starts at $399 for the 40mm model, and if you go for the larger case size for either, you’ll pay $30 more. Adding cellular connectivity adds $50 for the SE and $100 for the Series 9. The latter also comes with the option of a stainless steel case, plus cellular and GPS, and starts at $699. The Apple Watch Ultra 2 has just one price: $799 for a titanium 49mm case with both GPS and cellular power.
The Apple Watch Series 9 happens to be our favorite smartwatch, period. It’s a notable improvement over the previous generation, with new features like Double Tap, onboard Siri requests, a brighter screen and a new ultra wideband (UWB) chip that can help you pinpoint your misplaced iPhone 15 using the FindMy app.
In her review, Engadget’s Cherlynn Low spent some time working with the Double Tap feature and, while it took a little practice to get the tapping cadence correct, she found it actually did make her life easier. You can use it to dismiss a timer or an alarm, play music or reply to messages. Double tapping also pulls up the Smart Stack, the sequence of watchOS 10 widgets available with the latest software update. You can customize a few of the gesture’s actions, including how it navigates the Smart Stack and music playback.
The Series 9 also handles on-device processing of Siri requests. Though we didn’t notice a huge difference in response time between our review unit and the Series 8, we did like that it lets you ask Siri to start a workout when you’ve left your phone at home. Apple also improved the Raise to Speak feature, using a two-second audio buffer from the always-on mic to better anticipate your Siri needs. Ideally, you should be able to lift your wrist and say your requests without having to use the wake words. We found it only worked half the time, but when it did, it was “almost magical.”
All new tricks aside, the Apple Watch 9 is a steadfast companion for your iPhone, letting you see and respond to notifications without pulling out your handset. The various sensors can give you insights into your overall health and the fitness tracking tools, and Activity rings are both reliable and motivating. We do wish the battery lasted a little longer; you can’t typically get more than a day of use before needing a recharge, which can make it difficult to use the sleep tracking functions.
Apple didn’t make a new generation of the Apple Watch SE when it updated its other two wearables in September, but you still get a lot for just $250. Cherlynn also reviewed the SE when it came out in 2022, calling it “the best smartwatch for the money.” It uses the same chip as the original Ultra and the Series 8, and in our review of the new Series 9, Cherlynn “barely noticed a difference in performance” compared to the previous generation.
That said, there are some trade-offs. You won’t get an always-on display, blood oxygen monitoring or a temperature sensor. The SE also can’t support the new Double Tap feature and requires your phone to be nearby for Siri requests (if you don’t have a cellular-enabled model). Materials-wise, the SE face is covered in Ion-X glass, which is less robust than the sapphire crystal on either the stainless steel Series 9 or the Ultra 2.
That said, the SE has more in common with its pricier sibling than not, including crash detection, heart rate monitoring, emergency calling, and 50 meters of water resistance. Though the screen isn’t quite as bright as the pricier models, we thought it was crisp and easy to read, even in bright sunlight. The fitness tracking is accurate, the design is lightweight and comfortable and the processor is snappy. If you’re looking for a starter smartwatch and don’t mind the few missing features, the SE is still the way to go.
Apple announced the Apple Watch Ultra 2 at the same event as the Series 9. The Ultra is a big, feature-rich smartwatch with plenty of tools for athletes and outdoor adventurers. It comes in just one variation: a 49mm titanium case with both cellular and GPS connectivity. And interestingly, the latest model carries the same $799 price tag as the previous generation (though the older model is now seeing significant discounts).
Engadget’s Cherlynn Low took the original Ultra out on a hike to take advantage of its outdoor-specific features and the Backtrack function actually saved her and our video producer Brian from taking an unintended detour in the wrong direction. The function lives within the Compass app and lets you set waypoints such as marking the parking lot before you set out. There’s an onboard siren that’s loud enough to alert passersby or emergency personnel to your whereabouts if you should need it.
For water-based activities, the Ultra 2 packs diving features that can measure water temperature, dive duration and gauge up to 40 meters of depth. For workouts closer to home, the dual-frequency GPS gives you more accurate route tracking and pace calculations. And the action button can be programmed to start a workout, control the stopwatch, trigger the flashlight, set a waypoint and more. Just note that we found it pretty easy to accidentally trigger the action button when trying to press the crown, so it may take a little practice.
The new S9 SiP chip enables Double Tap and on-device Siri processing, just as it does on the Series 9. The screen has been bumped up to 3,000 nits and while we didn’t get to take the new model on a hike, the original at 2,000 nits was plenty bright enough in direct sunlight. We like how the new Modular Ultra watch face makes great use of the oversized screen (though that’s also available on the original AWU.) The battery life remains the same at 36 hours, and we got about three days of moderate use out of the Ultra before needing a recharge. The low power mode is particularly impressive, squeezing out many extra hours from a near-empty watch.