The Apple Watch Ultra 4 is coming, and if the latest leaks are accurate, Apple is planning its most significant redesign since the Ultra line launched. But there is a twist -- some of the most exciting rumored features might not make the cut after all.
Let us break down what is new since our last update, what is still uncertain, and what it means for the competitive landscape.
What Is New Since March
Our last Ultra 4 piece covered the basic rumor landscape: a fall 2026 launch, new sensors, and the usual chip improvements. Three months later, the picture is both clearer and more complicated.
A 15% Slimmer Case
The biggest surprise is the design direction. Multiple sources are now reporting that the Ultra 4 will be noticeably thinner -- around 15% slimmer than the current model. That is a meaningful change for a watch that has always been on the chunky side.
The trade-off has always been simple: bigger case means bigger battery. Apple has been willing to make that trade. But if they are moving to a slimmer design, it suggests either better power efficiency is freeing up internal space, or Apple has found a way to pack more density into a smaller footprint.
Either way, a thinner Ultra should be more comfortable for all-day wear. Whether athletes who wanted a rugged device are as thrilled is another question.
Touch ID: Coming -- Or Is It?
This is where the rumors get messy.
Back in March, we noted that code had surfaced suggesting Apple was working on Touch ID for the Ultra 4. The internal codename reportedly appearing in Apple's systems was "AppleMesa." The most likely integration points were the Digital Crown or the Action Button.
Here is the problem: a May 2026 report from MacRumors, citing a prominent leaker, pushed back hard. The report suggested Apple has deprioritized Touch ID for this generation, choosing instead to prioritize battery capacity and new sensor hardware.
So which is it? Touch ID might still happen, but it is no longer a sure thing. The "AppleMesa" codename proves Apple was at least working on it. Whether it ships in September is now an open question.
If Touch ID does arrive, expect it embedded in the Digital Crown or Action Button -- the two hardware elements that could realistically house a fingerprint sensor without major case redesign.
The S11 Chip
This one is straightforward. Apple is moving from the S10 chip (Ultra 3) to an S11 chip in the Ultra 4. The S-class chips have historically delivered modest year-over-year improvements in speed and power efficiency.
The S11 should continue that trend. Do not expect dramatic performance leaps, but expect better efficiency and slightly snappier interface responsiveness.
Double the Sensors?
One newer leak suggests Apple is roughly doubling the sensor components inside the Ultra 4. This aligns with earlier supply chain reports, but the specifics remain vague.
More sensors could mean better health data accuracy across the board. It could also mean Apple is preparing hardware groundwork for features that are not quite ready to ship yet -- blood glucose monitoring is the obvious candidate, though most sources agree that is still years away.
The Things We Still Do Not Know
September is a few months away, and Apple has been good at keeping the lid on things. Here is what remains unclear:
Display technology: MicroLED was rumored for earlier Ultra generations but never materialized. Will the Ultra 4 finally get it, or is Apple sticking with OLED?
Battery life: This is the big one. If Apple shrinks the case by 15%, does battery life stay the same, improve, or get worse? The efficiency gains from S11 could offset a smaller battery, but we will not know until Apple announces.
Price: The Ultra 3 started at $799. With new sensors and a redesign, a price bump is possible. But Apple has been relatively price-stable on the Ultra line, so do not be surprised if it stays at $799.
Blood glucose: Still not happening this year. Apple has been working on non-invasive blood glucose monitoring for over a decade, and the engineering challenges remain immense. When it finally arrives, it will be huge. But the Ultra 4 is not that moment.
How It Stacks Up
If the rumors hold, here is how the Ultra 4 would compare to the competition:
| Feature | Ultra 4 (rumored) | Garmin Fenix 8 | COROS PACE 4 |
|---|---|---|---|
| Battery (GPS) | ~25+ hours | 50+ hours | 31 hours |
| Battery (smartwatch) | ~45+ hours | 28 days | 20 days |
| Multi-band GPS | Likely | Yes | Yes |
| Touch ID | Possible | No | No |
| Maps | Yes | Yes | Yes |
| Music storage | Yes | Yes | Yes |
The battery gap is real, and it is the one area where Apple still trails Garmin and COROS significantly. For serious endurance athletes, that gap matters. For everyone else, the Ultra remains the best smartwatch-athletic hybrid on the market.
The Bottom Line
The Ultra 4 is shaping up to be a more significant update than we thought a few months ago. The slimmer design is the biggest surprise -- it suggests Apple is listening to feedback about comfort without abandoning the rugged positioning.
Touch ID is the wildcard. Apple clearly explored it, and the "AppleMesa" codename is real. But the May 2026 report that it might be deprioritized is credible. We will know for sure in September.
If you are in the market for an Ultra today, the Ultra 3 is still a great watch. But if the slimmer design rumors are accurate, waiting for the Ultra 4 might be worth it -- especially if you have found the current model too bulky for all-day wear.
One thing is clear: the Ultra line is no longer Apple's experiment. It is a core product. And Apple is finally starting to treat it that way.