Apple Watch Series 8 review: A big upgrade for older WatchOS users

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The Apple Watch Series 8 is a highly refined Series 7 with three new features: Crash Detection, body temperature sensing, and a new Low Power Mode that gives it up to 36 hours of battery life. If you’re coming from a Series 3 or older, or you don’t already own an Apple Watch, you’re going to love the Series 8. 

It has narrow bezels for a premium look, advanced health and fitness sensors and features, an always-on display, and as much battery life as you can expect from a smartwatch. It truly impresses, even holding its own against the Apple Watch Ultra. 

But upgrading to the Series 8 isn’t for every Apple Watch owner. If you own the Series 5 or newer, you’ll find the Series 8 very familiar. It’s not radically different in terms of performance and use, especially if you update your Apple Watch often.

Series 4 owners may enjoy the Series 8’s always-on display, but even they will find the overall experience similar. Small, gradual updates have made this device a competitor for the title of best Apple Watch.

The Apple Watch Series 8 will astound you if you’re coming from Series 3 or older

The Apple Watch Series 8 retains the slim black borders around the display that was introduced with the Series 7, which makes for a sleeker look than pre-Series 7 models with thicker borders. It’s also extremely customizable, allowing you to swap out the band for any of the best Apple Watch bands on the market, or you could even add an Apple Watch screen protector to it.

It feels exactly the same as any other Apple Watch, and it’s perfectly comfortable to wear all day and night. The Series 8 weighs about the same as any other model, too, and while it isn’t heavy by any means, the second-generation Apple Watch SE, which we’ve compared to the Series 8 in-depth, is slightly lighter by about 0.2 ounces if you’re looking for the lightest possible Apple Watch. 

Spec-hunters will see that the Apple Watch Series 8 runs on Apple’s S8 processor compared to the S7 in the Series 7, but it’s basically the same S6 processor that was introduced to the Series 6 back in 2020. It’s unclear why Apple would call it the S8 rather than the S6, but it’s likely because the S8 is tuned specifically for the Series 8’s sensors. 

That sounds old in tech years, but the Series 8 runs smoothly and quickly, and I didn’t observe any need for it to be more powerful or faster during testing. And the Series 8 will have a longer lifespan because it is the newest.

Series 3 users will feel the biggest differences. The Series 3 has thick, square borders around the display that look antiquated compared to the Series 8’s thin and rounded borders. Series 3 users will notice smoother performance in every aspect, whether it’s using Apple Pay, fitness workouts, or swiping through screens.

Apple is also no longer supporting the Series 3 with software updates, and while it should last another year or so, upgrading to a new model like the Series 8 ensures you get the best performance and security updates. 

However, if you’re using the Series 5 or higher — particularly the Series 7 — we don’t think an upgrade is necessary unless you can take advantage of one of the new features, which I’ll go into later.

An all-around better health and fitness tracking experience

Antonio Villas-Boas/Insider

The Apple Watch is an excellent option to track health and workouts with its combination of accurate sensors, including GPS, altimeter, compass, heart rate, blood oxygen, and ECG (for heart rate rhythm). WatchOS 9 even provides the ability to track things like medications and supplements with the Medications app. It’s also water resistant down to 164 feet (50 meters), dust resistant, and crack resistant, making it very rugged for wearing in most environments. 

It also includes sleep tracking, and with WatchOS 9, the Series 8 gathers new data for how much time was spent in different sleep stages, like REM, core, and deep sleep. To be clear, any watch running WatchOS 9 got this sleep-tracking upgrade, too. 

The Series 8 has new body temperature sensors that measure body heat at night. It’s designed to predict ovulation and period cycles, and like any feature on any device, it’s something some may find helpful, while others may not find necessary. My wife, for example, wasn’t particularly excited about the feature — it’s there if you want it, or you can disable it if you don’t.

Concerns have been raised about the Series 8’s ovulation tracking data in the context of Roe v. Wade’s overturn, where that data could potentially be used against individuals. Apple has a stronger record for privacy than many companies, even against government intrusion. With that said, no data is truly immune — if you don’t want any risk whatsoever, you’re better off not using the feature.

Apple’s Health app in iOS says that measuring wrist temperature can also “provide insight into your well-being.” That’s incredibly vague, and in my weeks of testing, the Series 8 has failed to capture any wrist temperature data because I didn’t have Sleep Focus set to activate automatically during the sleep schedule I set in the Health app. For clarity, I have Sleep Focus enabled so that I can track my sleep, but the Series 8 needs Sleep Focus to be activated during my sleep schedule for the watch to record wrist temperature. 

Apart from the new body temperature sensors, owners of most older Apple Watches won’t find the Series 8 to do a significantly better job of tracking workouts or overall health. The relevant sensors in older Apple Watch models are just as capable as those in the Series 8 and are comparable with some of the best fitness trackers on the market. 

The new Low Power Mode preserves battery life by sacrificing utility

The Series 8 ends a standard day with about 55% at bedtime. That’s a full day of telling the time with an always-on display, receiving notifications, checking the weather, replying to a few messages, and taking a phone call. I didn’t manage to squeeze in a full workout during testing but a mile-long walk with a toddler in a backpack carrier doesn’t affect battery life much. 

Apple says the Apple Watch Series 8’s battery life can last up to 36 hours with a new feature called Low Power Mode, but it’s not something I’d use on a regular basis. It disables features you’d expect for power saving, like background heart measurements, but it also disables core features that make the Apple Watch useful in the first place. 

It disables the always-on display, which is one of the main reasons to buy the Series 8 over the less-expensive SE. And when your iPhone isn’t nearby, Low Power Mode disables incoming phone calls and notifications, too. Complications, like the weather or heart rate widgets, also update less frequently, and notifications can be delayed.

As such, it’s better suited for certain situations where you know you won’t be able to recharge the watch, like camping over the weekend, for example. 

If you want the Apple Watch’s full functionality for that camping weekend or an extended activity like a backpacking trip or triathlon, you’ll do better with the Apple Watch Ultra for its superior battery life. It can last 36 hours in normal use, and up to 60 hours in Low Power Mode, so Apple claims.

Crash Detection is one of the best new features in the Apple Watch Series 8 we hope you’ll never use

Crash Detection is easily one of the most meaningful upgrades in the Series 8, which detects if you’ve been in a car crash and automatically contacts emergency services if you don’t interact with the alert within 10 seconds. 

Since the Apple Watch Series 8, SE, and Ultra’s release in September 2022, Apple’s Crash Detection feature has already been credited for being helpful after a crash, if not saving a life. It’s also criticized for being so sensitive that it registers rollercoaster rides as a crash, sending emergency services to amusement parks unnecessarily. Apple is said to be refining the feature to avoid false crash detections. 

Clearly, it’s a feature you should avoid having to use at all costs but it could be crucial in an accident if you can’t reach your phone to call 911. To be accurate, we haven’t tested Crash Detection, nor do we want to. 

Regardless, the Series 8 is the biggest leap since the Series 6 in terms of safety. Alongside Crash Detection, the Series 8 includes Emergency SOS, Fall Detection, International Emergency, high-and-low heart rate notifications, blood-oxygen measuring, and ECG functionality to look for irregularities in your heart rhythm.  

Should you buy the Apple Watch Series 8?

The Series 8 is an ideal upgrade if you’re coming from the Series 3 or older. And if you’re still rocking the Series 4, you could justify the upgrade for the always-on display.

But unless temperature sensing or Low Power Mode are a must, owners of the Apple Watch Series 5 and newer should reassess whether they need the new features. The Series 8 is available at two prices: $499 including cellular connectivity, and $399 for GPS-only.

Regardless, those who do upgrade will be pleased by the Series 8’s design and solid performance, as the Apple Watch continues to be the best smartwatch you can buy.

If the Series 8 appeals to you but you’d like something more affordable, consider the second-generation Apple Watch SE. It doesn’t include the always-on display or the temperature sensors, nor does it include Apple’s advanced blood-oxygen and ECG health sensors but it tracks fitness just as well, and it comes with Crash Detection — all for $150 less than the Series 8.