Apple Watch Series 11 and Series 12 Buying Guide: 25+ Upgrades Compared

The Apple Watch Series 12 is now available for pre-order, and unlike last year’s model, it brings a substantial list of changes compared to its predecessor. Here’s everything new.

Last year, the 11 series introduced just four changes compared to the 10 series, making it perhaps the smallest generational upgrade in the device’s history. The 12 Series is a much more significant refresh, although it retains essentially the same design for a third year in a row.

It launches on Friday, September 18 at the same $399 starting price as the Series 11, which Apple has now discontinued. This guide lists all the differences between the Series 11 and Series 12 models to help you understand the changes:

The new ceramic case marks the first ceramic Apple Watch since the Series 5 edition in 2019, but it’s slightly larger than other models and weighs up to 52.9 grams in its 46mm Night Blue configuration. Even the aluminum and titanium models are now 1 mm wider and around 2 grams heavier than their predecessors.

At the same time, the display appears to have shrunk slightly, although its resolution remains unchanged. Apple lists the 46mm Series 12 with 1,196mm² of display area, 2% less than the Series 11’s 1,220mm², while the 42mm model drops 1.9%, from 989mm² to 970mm².

A slightly smaller screen in a wider body means thicker bezels, and Apple also appears to have moved the case back slightly around a larger front glass, which could make them even more prominent. The Series 10 saw a similar change in 2024, when its visible aluminum edge shrank compared to the Series 9, but its overall frame, including the black border under the glass, actually grew larger. The change is less drastic this time around, as the Series 12 retains the same basic case design. Here’s how the two generations compare in terms of size, weight and display area:

The new ceramic models, which have no equivalent in the 11 Series, are even larger and considerably heavier:

The most important upgrade between the two devices is the new health detection system. It uses a larger electrode surface area for better skin contact during ECG readings, redesigned photodiodes arranged in a ring for more efficient light capture, and larger, more energy-efficient green LEDs. The result is that Series 12 measures heart rate every five seconds throughout the day, 60 times more frequently than before, and samples HRV up to 24 times more often. Apple says this gives the Series 12 the most accurate heart rate detection of any wearable device.

This higher frequency data powers several new health features exclusive to Series 12. The Readiness app evaluates your recent activity, training load, vital signs and sleep score to produce a unique daily score out of 10, accompanied by a recommendation ranging from “Recover” to “Go”. There’s also a separate Recovery HRV metric, a daytime view in the Vitals app, and new complications on the watch face for real-time heart rate and step counts. Apple has also rebuilt its pedometer model and claims that the Series 12 now offers the most accurate step tracking of any smartwatch.

The Series 12 is the first model in two years to receive a new chip, with the S11 replacing the S10 that powered both the Series 10 and Series 11, itself almost identical to the S9 chip from 2023. The new model also has twice the RAM, with 4GB compared to 2GB in the Series 11.

The S11 chip enables Audio Intelligence, a new set of features exclusive to the Series 12 and Ultra 4. Live Rewind displays a transcript of the last 15 seconds of conversation with a double press of the Digital Crown, ‌Siri‌ Recap generates conversation summaries, sound recognition alerts deaf or hard of hearing users to sounds like sirens and doorbells, and Shazam can automatically identify music playing nearby. According to Apple, audio is processed in a hardware-isolated Secure Exclude on the S11 chip and is never recorded.

Daily battery life remains unchanged for up to 24 hours, or up to 38 hours in low power mode. Improvements focus more on training and recharging. The Series 12 offers up to 10 hours of battery life during an outdoor workout, which Apple says is 25 percent more than the Series 11, and 15 minutes of charging now provides up to 12 hours of use instead of eight.

All other aspects, such as screen resolution and brightness, 64GB of storage, 5G connectivity, and water and dust resistance, are all unchanged from the 11 series.

Is it worth upgrading?

For new buyers, the 12 Series is the obvious choice. It costs the same $399 price as the Series 11 at launch, while adding a more capable health detection system, double the RAM, and a considerable list of exclusive features. With a new chip and more memory, it will likely be better positioned for future Apple Intelligence features. The Series 11 is the best value option only when it can be found at deeply discounted prices, which is likely when third-party retailers sell out their remaining stock.

Last year we concluded that almost no users should upgrade from a Series 10 to a Series 11. This year the picture is more nuanced. For most Series 11 owners, there’s still no general reason to upgrade, as many key features are unchanged and ‌Siri‌ AI is coming to the Series 11 anyway. However, the Series 12 is worth considering if you rely on your Apple Watch for workout and recovery insights, as continuous heart rate tracking, recovery HRV, and readiness are all exclusive to the new model. Deaf and hard of hearing users may find sound recognition a compelling reason to upgrade, and some users will simply want the new ceramic finish.

Series 11 owners who are happy to wait may prefer to wait for next year’s “Series 13”, which is rumored to bring the first major redesign since the Series 10, including a new strap attachment system.

On the other hand, upgrading is much easier to justify if you own a Series 9 or earlier. Series 10 owners would benefit from a new slimmer design with a wider screen, a tougher display on aluminum models, and longer battery life on top of all of this year’s changes.