Apple Watch Series 12 vs. Ultra 4: 7 Key Differences You Need to Know Before Buying

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The foldable iPhone stole the headlines, but Apple’s newest wearables quietly packed the biggest upgrades. Both the Apple Watch Series 12 and Apple Watch Ultra 4 boast the powerful S11 chip, upgraded heart rate tracking, and new Audio Intelligence. Yet with massive gaps in battery life, materials, and off-grid durability, choosing between them comes down to a few critical trade-offs. Read on for a detailed breakdown of exactly what’s different to help you determine which watch is right for you.

Full Specs

Price: One Ultra 4 Costs the Same as Two Series 12s

At first glance, the pricing structure is straightforward: the Series 12 starts at an accessible $399 (42mm, aluminum, GPS), while adding larger sizing (an additional $50) or cellular (an additional $100) tops out the standard titanium model at $749. That makes it significantly cheaper than the $799 Ultra 4, which comes standard in a single 49mm titanium cellular configuration.

But there’s a wildcard: material upgrades. Choose the fancy new Ceramic Series 12, and the price jumps to $899 (42mm) or $949 (46mm). Add in the ultra-luxury Hermès editions ($1,399 for Series 12; $1,499 for Ultra 4), and both lines can climb into true luxury territory. But for everyday buyers watching their wallet, the Series 12 remains the clear entry-level choice.

Design: Massive Variety vs. Single-Frame Utility

If you want your pick of finishes, sizes, and materials, you should go with the Apple Watch Series 12. It comes in aluminum, titanium, or all-new ceramic versions, each in two sizes (42mm and 46mm). Aluminum is available in black, gray, gold, or bronze finishes; titanium in radiant gold or natural; and ceramic in white or blue.

The Ultra 4, on the other hand, is just one size with two flavors: black or natural titanium. If you want some color or have smaller wrists, the Series 12 is the watch to go with.

Apple Watch Series 12 (Credit: Eric Zeman)

AI Features: Audio Intelligence Is Always Listening (If You Want)

Both the Series 12 and the Ultra 4 use Apple’s new S11 chip, which enables some new AI tricks their predecessors won’t get. The biggest one is Audio Intelligence, an Apple Intelligence feature that lets the watch listen to you, your conversations, and your surroundings all day, providing AI summaries and other information. It can rewind a live conversation with a 15-second text snippet, or give a full summary afterward with a title and key points. It can also notify you of sounds like alarms and doorbells, if you’re hard of hearing.

Apple says it approaches Audio Intelligence with privacy in mind, and that the S11 chip has a dedicated hardware section for locally processing and then deleting any audio it records. It also claims that speakers aren’t identified or attributed, and that sensitive information isn’t kept. I’m leery of any always-on AI, but you should be able to just turn it off on either watch if you don’t want to engage with it.

Health and Fitness: All-Day Heart Rate Tracking

Even if you don’t want to use Audio Intelligence, AI powers some of the Series 12 and Ultra 4’s new health features. They can provide a holistic readiness score, ranging from zero to 10, to let you know how much energy you have, and give you a recommendation of just how hard you should train that day. The iPhone Health app has also been redesigned and offers even more holistic information, including a Longevity tab that can tell you your body’s Health Age. The S11 chip also improves the pedometer function on both watches, providing more accurate distance measurements and allowing you to monitor individual steps in real time.

Apple Watch Ultra 4 (Credit: Andrew Gebhart)

Beyond AI analysis, both new Apple Watch models have redesigned always-on heart rate sensors. They can measure your heart rate every five seconds throughout the day, rather than just periodically, as previous models did. They also measure heart rate variability (HRV) up to 24 times more often than before.

For general health and fitness, the Series 12 and Ultra 4 are on equal footing. When you get into more extreme outdoor activities, though, that changes, and that brings us to the next section.

The core connection features of the Series 12 and Ultra 4 are the same, with support for dual-band Wi-Fi 4, Bluetooth 5.3, and 5G and LTE cellular connectivity. The Ultra 4 builds on that with satellite connectivity for messages and emergency signals, even if you’re outside of cellular coverage, which could prove useful if you enjoy long hikes on remote trails. It also has dual L1/L5 GPS compared with the Series 12’s L1 GPS, enabling more precise location tracking.

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Durability: City-Proof Ratings vs. Extreme Dive Certification

Once again, while the Series 12 and Ultra 4 are on equal footing for day-to-day work and play, the Ultra 4 wins when you look to the extremes. Both are IP6X-rated for dustproof and waterproof protection, but the Series 12 is only rated for submersion to a depth of 164 feet and is not recommended for diving. The Ultra 4 is water-resistant to 328 feet and safe for diving to 141 feet, and has EN13319 certification to prove it. It’s also tested to MIL-STD 810H, which means it can be put through environmental peril that the Series 12 might not survive.

Apple Watch Ultra 4 (Credit: Andrew Gebhart)

Battery Life: 24 Hours vs. Multi-Day Endurance

We still need to test them ourselves, but based on Apple’s estimates, the Ultra 4 can last more than twice as long as the Series 12. Apple estimates a battery life of 50 hours for the Ultra 4 with normal use compared with 24 hours for the Series 12.

Those numbers might diverge even wider based on what we’ve seen with previous models. Apple is usually conservative with its battery life estimates, and both the Apple Watch Series 11 and the Ultra 3 lasted far longer than Apple said they would. In testing, the Series 11 lasted 43 hours, compared with a claimed 24 hours, and the Ultra 4 lasted 63 hours, compared with a claimed 42 hours.

Considering the always-on heart rate monitors in the newest models, the Series 12 and Ultra 4’s real-world battery lives might be closer to Apple’s estimates this time around, but either way, it’s safe to say that the Ultra 4 will last much longer than the Series 12.

Verdict: Everyday Versatility or Extreme Performance?

It’s hardly shocking that the Apple Watch Ultra 4 looks like the superior device—it’s always been Apple’s top-tier feature showcase. But that premium performance comes with a premium price tag (unless you have your eye on a luxury ceramic Series 12). Since both watches share the same S11 chip and continuous heart rate tracking, their everyday performance is virtually identical. If you need multi-day battery life, off-grid navigation, or ocean diving specs, spend the extra money on the Ultra 4. Otherwise, the Series 12 offers all the smarts you actually need in a far more wrist-friendly design.