Technologies

Apple Watch Series 9 vs. Ultra 2: Don’t Get the Wrong One

After a month wearing both, this one is still on my wrist.

The Apple Watch Series 9 and Apple Watch Ultra 2 have more in common than you might realize, even though they’re very different watches on the outside. While the $799 Ultra 2 is a tougher, bigger and pricier watch than the $399 Series 9, internally they’re almost the same. They share the same S9 chip that supports features like Double Tap, on-device Siri and speedy performance.

So how do you separate the two? Price is likely your first consideration. The $799 Ultra 2 only comes in one 49mm size with a titanium case and LTE connectivity is included.

But the $399 Series 9 is more complicated. First, you need to choose between a 41mm or 45mm size. Then, pick an aluminum or stainless steel case and whether or not you want the LTE version. Indeed, the 45mm Series 9 in stainless steel costs $749, which puts it squarely in the ballpark of the Ultra 2.

The price factor might not be as clear-cut as you first thought. To help you make the right decision, I wore both watches for a month. Here’s what I found.

Apple Watch Ultra 2 Screen: Bigger, brighter than Series 9

The Apple Watch Ultra 2’s 49mm case is bigger than the 45mm Series 9, but the screen itself is also slightly larger. That means you can fit slightly more on the Ultra 2’s screen, helpful if you are using an app like Maps for example.

The easiest way to spot the size difference is to boost the text size to the maximum on both watches. Part of the text gets cut off on the Series 9 compared to the Ultra 2, like in the image below.

Apple Watch Series 9 vs. Ultra 2 screen size

But the biggest difference in day-to-day wear is screen brightness. The Ultra 2’s screen gets brighter than the Series 9 at 3,000 nits vs. 2,000. I’ve had zero issues seeing the Series 9 indoors or outdoors, but having a little extra brightness on the Ultra 2 is nice for readability, especially for workouts in bright sunlight.

It also gives the flashlight a boost. You can turn the digital crown on the Ultra 2 to force the screen to its brightest setting when using the flashlight, which is helpful in dark situations. I went spelunking with the first Apple Watch Ultra, which shares the same screen brightness as the Series 9, and the Ultra 2. The additional brightness on the Ultra 2 really did make a difference when illuminating the rock face.

Apple Watch Series 9 vs. Ultra 2 brightness

Apple Watch Series 9 might be better for smaller wrists

There’s no ignoring that the Ultra 2 is a large watch. Coupled with the chunkier digital crown and flat display, it stands out a lot more than the Series 9. My wrist measures 152mm and even though the Ultra 2 looks hefty, it’s surprisingly comfortable on a small wrist and I wear it all the time.

But there’s no ignoring the fact that the Ultra 2 might be too large if you have an even smaller wrist than mine. That means you might gravitate toward the Series 9 just to have the option of a smaller case size. I also found the Series 9 is more comfortable to sleep with if I do want to track my time in bed.

The Ultra 2 is, however, designed to be a tougher watch than the Series 9. Its titanium case is slightly raised to give more edge protection to the sapphire crystal display. The Series 9 display has two different coverings: Ion-X glass if you get the aluminum case, or sapphire crystal on the stainless steel case

Both are IP6X dust-resistant and water-resistant, but the Ultra 2 can go down to a depth of 100m compared to 50m. It also has an exclusive Depth app and support for the Oceanic Plus app that turns the watch into a dive computer.

Apple Watch Ultra 2 Action button speaks my love language

The Ultra 2 has another significant design feature that sets it apart from the Series 9. Just like the Action button on the iPhone 15 Pro and Pro Max, you can press it to quickly launch your favorite workout, the flashlight, the stopwatch and other preset tasks.

My favorite way to use the Action button is to trigger a Shortcut, which is a quick way of accessing a favorite feature or tasks in an app. You can program a Shortcut yourself using the app of the same name on the iPhone.

One of my top Shortcuts is to navigate home from my current location, but you could also use it to control connected home appliances, or toggle on a focus mode. The possibilities are almost endless. I even made a Shortcut to Rickroll myself (yes, seriously). You can see that in action on the video on this page.

All is not lost on the Series 9 if you like Shortcuts. You can still set a complication on the watch face to launch a Shortcut, it just requires an extra tap on the screen to confirm you want to run it.

Both Apple Watch Ultra 2 and Series 9 have Double Tap and Siri

You can use the Double Tap gesture to control both the Apple Watch Series 9 and Ultra 2. It’s powered by the S9 chip and works exactly the same on both watches. When the screen is active, you can double tap your thumb and forefinger to complete a task, rather than touch the screen. For example, raise your wrist and double tap your thumb and forefinger to reply to a message with dictation, then double tap to send.

It’s helpful, accurate and works in many of Apple’s apps. You can answer a call, change tracks and start or stop timers. For third party apps, it will generally perform the default action when you double tap. I use it to quickly reply to Slack messages from colleagues when I’m unable to grab my phone or type a response out at my computer.

It works the same on both watches, because they run the same chip. On-device Siri is also the same, so the watches don’t have to ping the cloud when you ask Siri to do something that doesn’t require the internet. That includes tasks like starting a workout or setting a timer. They also both have 64GB of internal storage, great if you like to put music or have lots of apps on your watch.

Apple Watch Ultra 2 has some special tricks

While you’ll get the same great WatchOS 10 experience and a wide selection of apps on both watches, the Ultra 2 has additional features that swing the pendulum in its favor.

First, watch faces. You might not think this is enough to make you choose the Ultra 2 over the Series 9 but the exclusive faces are nice: Modular Ultra and Wayfinder. They fit a lot of detail on the screen and have room for seven or eight complications, respectively. And they have a dark mode that turns either watch face red when the light sensor detects it’s dark outside.

The Ultra 2 also has a three-mic array to help cut out more wind noise when on calls, plus dual speakers which get louder than the Series 9. I took both watches outside and recorded the call audio so you can hear the difference on the video on this page.

Then there’s the matter of connectivity. The Ultra 2 has LTE as standard, whereas you need to buy the specific LTE (or cellular) version of the Series 9 if you want to use your watch without your phone nearby. Once you add a data plan from your existing wireless provider, you can leave the iPhone behind and still connect to your favorite apps, send messages or make calls from your wrist.

Both have the second-gen ultrawideband chip which means you can find your phone from the watch with precision finding, as long as you have an iPhone 15. If you have an older iPhone, ping your phone from your watch to make it ring.

Apple Watch Series 9 and Ultra 2 have very similar health tracking

Both share a temperature sensor, blood oxygen sensor, ECG or electrocardiogram app, as well as the option for high and low heart rate and irregular heart rhythm alerts. The heart rate sensor is also the same on both watches and accurate when compared to a chest strap.

Fitness tracking is identical and you keep track of your progress using the Apple Watch Activity app. You can also connect Bluetooth accessories like power meter pedals to both watches, create multisport workouts, and keep an eye on your heart rate zones.

A compass app, back track and waypoint functionality is standard on both watches, as well as car-crash detection, fall detection and emergency SOS.

The differences come down to the Ultra 2’s 86dB siren for safety and GPS. The Ultra 2 uses dual-band GPS, both L1 and L5 bands, while the Series 9 uses L1. That means the Ultra 2 is more accurate at tracking distance and route information in built-up areas specifically. But for regular outdoor use for runs in the park or tracking a bike ride on the trails, the Series 9 still does a great job.

Apple Watch Ultra 2 has the best battery life, period

The Ultra 2 knocks the Series 9 out of the park on battery life. It doesn’t matter how you use the watch, whether you’re running a marathon or just using it as a watch to tell the time and get notifications, it runs rings around the Series 9.

Apple Watch Series 9 vs. Ultra 2 battery life

Apple officially rates the Series 9 at 18 hours and the Ultra 2 at 36 hours or runtime. But this is conservative, because I’ve been able to stretch both a lot longer. With what I’d call regular use (phone notifications, the always-on display, a GPS workout and sleep tracking) you can get a day and a half from the Series 9 before charging. With the same use, I can get closer to three full days from the Ultra 2.

Both have a low power mode to extend the battery even further, but of course your mileage will vary depending on how you use the watch. Resource-intensive tasks like using LTE and listening to music over Bluetooth will deplete your battery sooner. We have more on specific battery life usage in our Apple Watch Series 9 and Ultra 2 reviews.

Both also support fast wireless charging, as long as you have an 18-watt or higher adapter. The Series 9 charges faster than the Ultra 2 from flat to full because it has a smaller capacity battery.

What’s the difference between Apple Watch Series 9 and Ultra 2?

With a similar overall feature set, including Double Tap and on-device Siri, the main differences between the Apple Watch Series 9 and Ultra 2 comes down to size, price and battery life. The Series 9 is less expensive, has a slimmer design and two size options compared to the Ultra 2. But you will need to charge it more often.

Both Apple Watches are a great pick if you want a versatile smartwatch that works with the iPhone. After wearing both for a month, the Apple Watch Ultra 2 is my favorite for two main reasons, if price wasn’t my primary consideration. Its long battery life means I no longer have battery anxiety about needing to charge it every day. And the Action button is so helpful and customizable, it makes using the watch much more enjoyable and convenient.

Technologies

Watch Out, Meta. I Tried Alibaba’s Qwen Smart Glasses and They’re Mega Impressive

These AI-focused smart glasses are available now in China but will roll out internationally later this year.

Mobile World Congress in Barcelona might be a European tech show, but for the past few years, the event has largely been dominated by Chinese phone companies such as Xiaomi and Honor. This year, they were joined by tech giant Alibaba, which launched its Qwen smart glasses at the show — and having tried them, all I have to say is, Meta should watch its back.

The Qwen glasses are among the first wearable devices Alibaba is building on top of its Qwen AI family of large language models, and the company brought two different models to the MWC.

The first pair, the Qwen S1 specs, have a heads-up waveguide display etched into the lenses, and serve as a rival to Meta’s Ray-Ban Display model (minus the gesture control). My first impression of these AR glasses was that they were light and comfortable to wear — I wouldn’t have known that they were smart glasses by their weight alone. At the end of each arm are swappable batteries, which snap off easily so you can keep the glasses running for longer when you’re on the go.

I activated the glasses with the phrase «Hey Qwennie,» which it picked up with its five microphones. I then asked it to complete a range of basic tasks, including asking the device to take a photo and to tell me what I was looking at when I held a photo of Barcelona’s Sagrada Familia in front of my face.

I could see a miniature version of the photo I captured in the green display, and the glasses were able to answer my architectural query both by displaying text in the heads-up display and through the bone conduction built into the arms of the S1. Perhaps my favorite feature, though, was the turn-by-turn directions. This feature felt like it could become essential for navigating a busy city, and far more convenient than using a phone or smartwatch.

I also tried out the teleprompter feature, which scrolled as I read out loud from the text appearing on the display but must confess I didn’t find it quite as easy to follow as a similar demo I tried earlier in the week on the MemoMind One glasses. With the Qwen booth assistant talking to me in Chinese, I was able to see and hear the English translation of her words on the display and in my ear simultaneously, although there was enough of a delay to prevent our communication from being entirely smooth.

The second pair of glasses Alibaba brought to the show were the Qwen G1 glasses, which lack the heads-up display present on the S1, but otherwise offer pretty much the same features thanks to the microphones, cameras and bone-conduction.

On the whole, I was impressed by the look, feel, sound quality and capabilities of these glasses, which for many people might be their first introduction to Alibaba’s Qwen AI (by way of the Qwen App, which is integrated with the specs). In China, where preorders for the glasses are already live, people wearing the glasses will be able to complete tasks such as ordering food or hailing a cab completely hands free.

Alibaba said pricing for the G1 glasses will start at around $275 (for comparison, Meta’s Ray-Ban Gen 2 glasses cost $379), but didn’t say how much the more advanced S1 glasses will cost. Official sales in China will commence on March 8, with Alibaba promising an international rollout featuring integration with popular global services scheduled for an unspecified date later in 2026.

Technologies

Softness and Brightness Blend to Stunning Effect in TCL’s Nxtpaper AMOLED Phone Display

An anti-glare screen that’s still radiant and vivid? Sign me up.

I’ve always been impressed with TCL’s easy-to-read Nxtpaper technology. Sitting somewhere between E Ink and a more traditional screen with built-in anti-glare tech, there’s a softness both to the look and feel of a Nxtpaper display that makes it a real pleasure to use.

But if I were asked whether I’d be happy to replace my regular phone with one that had an LCD Nxtpaper display, the answer has always been no, for one simple reason: brightness. The vivid colors that we’re accustomed to on most phones screens tend to look dull on Nxtpaper, and I just wouldn’t be willing to compromise on radiance, in spite of the many good qualities Nxtpaper brings to the table.

Until now, that is. Among the cool phones and weird tech on display at Mobile World Congress 2026, I saw a Nxtpaper phone that might have changed my perspective. TCL showed off an upgraded AMOLED version of Nxtpaper stopped me in my tracks. It blended the luminosity of AMOLED and the softness of Nxtpaper to stunning effect, in a way that would genuinely make me reconsider my stance on owning a Nxtpaper phone.

The screen offers 3,200 nits of brightness, and has a circular polarization rate of 90%, which means it closely resembles natural light. TCL has managed to reduce blue light emission as low as 2.9%, and the display dynamically adjusts brightness and color temperature in tune with the body’s natural circadian rhythms.

The one drawback I can see for using Nxtpaper on a phone screen is that it might not be ideal for taking, viewing and editing photos. In my brief demo at MWC, I took a selfie and noticed the colors didn’t look especially true to life. But it’s important to note that TCL is still developing this technology, so it remains a work in progress and my brief time using it likely won’t be an accurate reflection of a final product.

In all, this is real leap forward for Nxtpaper. Although TCL hasn’t announced any devices featuring the technology yet, it likely will do in due course. I’d personally like to see it on a laptop — as I spend all day staring at my screen both reading and writing, it seems like the perfect application of this tech. I can’t wait to see where it ends up.

Technologies

AI Data Centers: What to Know About Their Water and Energy Use

OpenAI’s Sam Altman says AI’s water concerns are «totally fake.» The truth about AI’s impact on natural resources is more complicated.

When people find out I’m a journalist who covers AI, they often ask about the drastic energy consumption of AI data centers. Are these centers using up all of our drinking water? How is this tech affecting the environment? Is AI going to kill us all? The questions range from curious to downright dystopian.

Sam Altman, the CEO of OpenAI, recently faced criticism after calling some of these concerns, particularly those around water, «totally fake.» It all stems from a Q&A session hosted by The Indian Express newspaper. Around the 26-minute mark of the interview, Altman was asked to defend certain criticisms of AI, including the amount of natural resources it takes to power large language models like ChatGPT.

Altman responded, «(criticism of AI for overuse of) water is totally fake,» saying that while extreme water use «used to be true,» OpenAI no longer does evaporative cooling. He said estimates that 17 gallons of water are used for every chatbot query are no longer accurate.

«This is completely untrue and totally insane, [and has] no connection to reality,» he said. He then goes on to address AI energy consumption, calling the concerns «fair» but arguing that it should be evaluated as a whole, not per query, since some queries, like videos, are more intensive to generate than text conversations. (Disclosure: Ziff Davis, CNET’s parent company, in 2025 filed a lawsuit against OpenAI, alleging it infringed Ziff Davis copyrights in training and operating its AI systems.)

Still, Altman says, «we need to move toward nuclear or wind and solar (power) very quickly.»

Questions involving data centers and water are complicated.

Do AI data centers strain land and power systems?

Altman’s remarks come amid timely, ongoing debates over data centers and their energy use.

CNET’s Corin Cesaric dove into the issue of AI’s energy use last year and found the cost of training and running ChatGPT, Gemini, Claude and other generative AI tools to be «staggering.» The US accounted for the largest share (45%) of global data center electricity consumption in 2024, according to the International Energy Agency.

As for water: Two Google data centers in Council Bluffs, Iowa, alone used 1.4 billion gallons of water in 2024, enough to fill about 28 million standard bathtubs. Google has 29 data centers worldwide. Meta’s data centers also accounted for about 1.39 billion gallons of water used in 2023.

While we don’t currently have statistics from OpenAI, Meta, or Google on their natural resource consumption in 2025, it’s safe to bet that data center energy and water use will rise as more people use generative AI.

How do AI data centers use water?

Considering ChatGPT now has close to 1 billion weekly users, and OpenAI has estimated that it handles close to 2.5 billion prompts every day, that’s an astronomical amount of data to manage. And because of this demand, the powerful computers that train the AI models and process their prompts get extremely hot. Think of how your phone and laptop heat up when running demanding tasks. If servers overheat, they can slow down or become damaged. This is where water comes in.

Traditionally, water in AI data centers is used in two ways: evaporative cooling (consuming water) and closed-loop systems (recirculating water).

Evaporative cooling is a ventilation technique that uses the natural process of evaporation to convert liquid water into water vapor, which absorbs heat during the process. Closed-loop cooling is a more resource-efficient process that reuses the water to dissipate heat without evaporation or consumption.

OpenAI said in a January announcement that it is «prioritizing closed-loop or low-water cooling systems» to minimize water use. This does lend credence to Altman’s recent claims that OpenAI’s water use is not as high as the 17 gallons per query estimate, but we don’t yet have exact figures for OpenAI’s 2025 water use.

OpenAI says it is moving away from the more costly evaporative cooling systems. However, 56% of data centers still use this method in some form over closed-loop systems, according to a January 2026 report from global water technology company Xylem and market research firm Global Water Intelligence. The research anticipates that AI water consumption will spike nearly 130% by 2050.

How much energy does AI use?

Powering AI and these massive data centers is demanding.

Generative AI chatbots use more energy than traditional search engines like Google or Bing. One estimate calculated that a single chatbot query requires 10 times more electricity than a Google search. On average, a single text query takes about 0.24 to 3 watt-hours, but AI-generated videos and images require much more electricity.

An August 2025 report from Google details Gemini’s energy use. The report states «the median Gemini Apps text prompt uses 0.24 watt-hours (Wh) of energy, emits 0.03 grams of carbon dioxide equivalent (gCO2e) and consumes 0.26 milliliters (or about five drops) of water.» Google equates this energy consumption to powering a microwave for 9 seconds.

Is solar a valid alternative?

Even though AI models require 24/7 power, solar energy is a viable and scalable option for powering AI data centers.

OpenAI announced a multi-billion-dollar venturein October 2025 to explore new energy generation with solar and battery storage. Meta, Microsoft, Google and Amazon all expanded their solar power use across the US in 2025.

While renewable solutions could be the path forward, solar (or wind) energy is still only part of the mix of energy generation used by data centers. They generally rely on the grid itself, which is still largely powered by the burning of fossil fuels like natural gas.

Where we stand

The conversation around AI and water use is moving from unconfirmed claims to measured scrutiny. Communities and policymakers are now pushing for transparency and sustainable practices, aiming to ensure that AI’s rapid growth doesn’t come at the expense of local water resources or the local electricity grid. As AI continues to grow, so, too, will the debate about how best to balance technological innovation with environmental responsibility.