Xiaomi 15 Ultra review: All-rounder, all-premium, no-nonsense

Note: This review was first published on 25 March 2025.

How can Ultra do more for you?

Xiaomi 15 Ultra is the 2025 representation of Xiaomi’s best-in-class mobile phones. 

To differentiate it from its regular variant, it has an exaggerated profile that screams more of nearly everything: more cameras with more zoom range, more battery, and more display.

Also returning is its partnership with Leica, although most of its imaging perks are catered to professional videographers. Regular consumers will instead enjoy more stable video recording with improved stabilisation and better coverage thanks to its 14 to 100mm photography zoom range across four rear cameras, which we will briefly touch on below.

The TL;DR version:



Xiaomi 15 Ultra is a strong premium all-rounder, even if the refinements are minor.



Find it at Xiaomi’s official online store and official platforms like Shopee and Lazada.

The phone features a competent AMOLED panel with top-end perks and eye comfort certifications. Underneath the display is a class-leading Qualcomm Snapdragon 8 Elite chipset, waiting to blow users away in gaming or day-to-day use.

While its fundamentals are similar to those of the preceding Xiaomi 14 Ultra, Xiaomi still tried to clean things up a little. A mildly redesigned exterior and repackaged AI tools (now called Xiaomi HyperAI) act as the glue holding its updated HyperOS 2 interface—all of which we touch on below, too.

Perhaps a true upgrade is the 5,410mAh silicon-carbon battery, which is more than before. We’ll unravel if that gives us more battery life or if the increase resulted in other outcomes.

Seeing how the S$1,699 Xiaomi 15 Ultra (16GB RAM + 512GB storage) is mostly a refinement of a Leica-branded phone it always wanted to make, does that mean Xiaomi has figured out that an excellent polish is the secret to an Ultra breakthrough? 

Or, will Xiaomi’s polish be superficial and miss out on the things that really matter in a flagship-class phone?

Let’s find out.

Design: better, but not really

Xiaomi 15 Ultra stuck to a classic Chinese Android phone design: a slightly curved display, straight-edged rims, and an oversized island for its rear cameras. It’s a form factor that’s tried and proven true, even if it’s not exciting or pretty.

The comically large camera housing isn’t any less funny now, either. It adds a clunky heft to the 226g phone, which is already 9.35mm thick without it. It also doesn’t help that the Xiaomi 15 Ultra has an unusually large 75.3mm width (more than the typical 72-74mm wide handsets). 

(For reference, Xiaomi 14 Ultra is thinner and lighter).

This combination of numbers means the Xiaomi 15 Ultra feels chunky, and slapping on a (provided) silicone phone case exacerbates it. That said, the phone's bulk is understandable given that it has a larger-than-average 1-inch type main camera sensor. But even then, it must be said that it pushes the limit even among big, heavy handsets.

Xiaomi should look into reducing the thickness and weight of its most premium flagship smartphone before it starts wearing out its users in day-to-day use.

Despite its somewhat clumsy handling, this year’s Ultra has a noticeably better fit and finish. 

It features cleaner-looking railings that no longer overextend to the rear like how the Xiaomi 14 Ultra did. Unlike the old double-layered island, the new camera ring has a thin, watch-like detail around its barrel. We got the White rear again, and this iteration came with a very pleasant-looking pattern that looks like a forbidden lovechild of marble and silk. 

Sadly, these superficial changes do nothing to hide or help its bulk. Then again, Xiaomi's Ultra models have also been large phones. One upside to its heft is that the Xiaomi 15 Ultra boasts IP68-rated water and dust resistance, which should make it a fairly durable phone. Overall, It's a lot of power built into one handset, and it is well-received by its fans across the globe.

Display delivers on its premium promise

The 6.73-inch AMOLED display yields no surprises, which is a win in our books since we’ve come to expect high-end panels on Xiaomi’s Ultra series phones. The Xiaomi 15 Ultra offers QHD+ resolution (3,200 x 1,440 pixels) paired with 1-120Hz refresh rates, a high 300Hz touch sampling rate, and 3,200-nit peak brightness. 

It also supports various types of HDR, including HDR10+ and Dolby Vision. These perks mean the display can handle most of the content you throw at it, even 60FPS streamed videos or properly optimised 120Hz games.

Our two display callouts are Xiaomi’s Shield Glass 2.0 (which we didn’t test because we didn’t want to break the phone) and “wet touch technology” (which we did, and it works well). Even with wet fingers, the touchscreen stays just as responsive and accurate when swapping, tapping, and unlocking it. We think this is an excellent way of using the phone’s IP68-rated water and dust resistance beyond mere protection.

The stereo dual speakers are reasonably loud at full volume. Like most phones, they are biased towards lower frequencies, granting strong bass. Otherwise, they’re typical at handling vocals (mids) and other instruments (mid to high). One thing we noticed, however, is that the speakers are mildly off balance—the left side is noticeably softer in landscape mode. Maybe Xiaomi intentionally did this to encourage owners to get the Xiaomi Buds 5 Pro, which launched alongside this phone.

Xiaomi HyperAI

Xiaomi’s choice of operating system, HyperOS 2, should feel familiar to most Android phone users even if they’ve never tried it before. It’s an improved version of its old MIUI, which retired in late 2023 to give way to 2024’s HyperOS. HyperOS 2 is a 2025 update based on Android 15, with slightly more refined features and user experiences.

What’s new, however, is Xiaomi’s repackaging of its loosely scattered generative AI features. It’s marketed as Xiaomi HyperAI.

In a nutshell, the Xiaomi 15 Ultra has the following (not new) AI-powered features:

• AI Writing
• Speech Recognition
• AI Interpreter
• AI Search
• “AI Dynamic Wallpapers”
• AI Subtitles
• Built-in Gemini into power button (press and hold) and Circle To Search

Technically, Xiaomi's built-in Gemini is a fresh addition, but we won’t discuss these perks again since you can repeat the same experience on any Gemini-infused device (like the Samsung Galaxy S25 Ultra).

While the other AI functions have also been around for a while, we’d like to highlight the following interesting features we’ve tried.

AI Subtitles supposedly offers built-in, real-time translations for online videos, meetings, and video calls. After enabling it via Settings, we ran straight to the YouTube app to try it out with non-English content for translation to English text.

Unfortunately, we think AI Subtitles aren’t ready for videos or calls yet. The subtitling speed (and, to an extent, the AI processing and prediction) cannot keep pace with regular conversation and leaves out 80-90% of what was said. The screenshot above actually does not show how it misses out on banter by two other offscreen folks talking to the onscreen person.

The slow subtitling was consistent across various videos we tried, which fared even worse with TikTok content, where content creators typically mispronounce words or use slang in their clips (these add an extra layer of complexity and nuance).

That said, we don’t want to discourage Xiaomi from further growing AI Subtitles. While it’s far from usable in its current state, it holds the potential to be a unique, game-changing use of AI since it can mitigate (or even remove) language barriers in consumed media.

Another interesting feature is AI Dynamic Wallpaper. It takes a static photo from your Gallery to generate a slightly animated version that can be used on your Xiaomi phone's Lock Screen or Home Screen. 

It’s cloud-based processing, and it takes about three minutes per generation. In our trials, it’s decent at simulating background movement, like commuters walking away or cars moving past. However, it has far less creative liberty when animating portrait shots where people are the main subject.

(AI Dynamic Wallpaper is hidden in Settings > Personalisation > AI Dynamic Wallpapers).

The rest of the AI features are pretty typical, even if they take longer to resolve than Google’s Gemini. For example, AI Writing in the Notes app would display generated text at typical reading speeds instead of an instant text blast on-screen. 

Imaging Performance

The Xiaomi 15 Ultra has four Leica-powered rear cameras. Thanks to its ongoing partnership with Leica, the optimisations are hardware-based (lenses) and software-based (colour science).

Xiaomi 15 Ultra has Leica Vario Summilux aspherical lenses for all rear cameras, covering a 14mm to 100mm zoom range alongside different apertures of each rear camera lens (from f/1.63 on its main camera, to f/2.2 on its longer-ranged periscope telephoto camera).

The colour science shows up as two compulsory Leica shooting modes. Like previous Leica-infused Xiaomi mobiles, Leica Authentic replicates the darker, contrasty look that modern Leica digital cameras are known for, while Leica Vibrant offers a greater punch of colours that’s helpful when shooting in low-light or night conditions.

The four cameras are:

• 50MP main camera, Sony LYT-900 sensor, 1-inch sensor size, f/1.63 aperture, OIS, 23mm equivalent focal length
• 50MP ultrawide camera, f/2.2 aperture, 115° field-of-view, 14mm focal length, 5cm super macro
• 50MP floating telephoto camera, f/1.8 aperture, OIS, 70mm focal length
• 200MP ultra-telephoto camera, f/2.6 aperture, OIS, 100mm focal length

That’s how Xiaomi arrived at its “14-100mm” coverage for Xiaomi 15 Ultra Leica lenses. However, Xiaomi also said it has optical-like quality at 200mm, which likely means its ultra-telephoto also has in-sensor crop zoom.

Added perks include “step-less focal length adjustment, " which now goes from 23mm to 135mm. Also, its main camera has a 4-axis image stabilisation. We believe these will make street photography easier to take.

We also showcased its photography in an earlier feature, so the additional shots below bolster our opinion of Xiaomi 15 Ultra’s shooting capabilities.

With its 2x in-sensor zoom, the main camera covers an adequately wide focal range (23 – 46mm), making it a viable option for a variety of situations—from landscape, architectural, street, and even portraiture. Users who look towards having good portrait photos can appreciate the detailing and decent separation between subject(s) and background.

The ultrawide has proven reliable with minimal fish-eye distortion in the centre of the image, even if it falls slightly behind in light intake.

The rear cameras' AI is hard at work when bokeh is introduced. As you can see, the main camera shot keeps the bottles behind the taco reasonably focused to portray the scene correctly. At the same time, the 4.3x zoom could make the tacos the highlight of the image by blurring out the same drinks behind them despite adverse lighting conditions.

Besides highlighting how the in-sensor crop zoom uses the primary camera to achieve better detailing and contrast, it also shows how Xiaomi 15 Ultra's imaging competencies can bring out emotions and scenes. Based on our conversations with the protesters in this photo, this workers' strike sought to reduce working hours from 40 to 37.5 per week.

This image helps showcase Xiaomi 15 Ultra's main camera when taking low-light and night shots. The Leica Authentic filter makes getting details in darker areas challenging (see windows and balconies). Still, the contrasted shop lights, human traffic, and the overcast evening sky are all correctly interpreted otherwise.

All in all, Xiaomi 15 Ultra offers a pleasing set of rear cameras if you want to use its Leica colour filters. Its fundamental competencies, like noise, detail, and sharpness, alongside digital enhancements like bokeh, are superb, making it a reliable shooter for a fairly wide variety of photography styles.

Benchmark Performance

As one of Qualcomm's highlighted partners, it's natural that Xiaomi's best uses Qualcomm Snapdragon 8 Elite and it's the full 8-core version, too. For the average consumer, it's one of the best 2025 mobile processors money can buy, and it's also found in rival premium flagship alternatives we've collated in our table below.

Hit the link if you want to know more about the technical capabilities of the processor. 

Putting it to the test

To find out how the competitors line up specs and price-wise, check them out in this link.

To find out more about the tests we conduct and what they relate to, we've jotted them down here.

Benchmark performance remarks

Besides the benchmarks showing how the Snapdragon 8 Elite is dominant, it’s also clear that the Xiaomi 15 Ultra has good optimisation of the processing power available to the device and chipset in a well-rounded way.

CPU, GPU, and read/write speeds were all pulling in numbers that could match up or even rival Samsung Galaxy S25 Ultra’s customised version of the chipset. The phone kept to a comfortable 37°C even in the heat of benchmarking.

Battery Life

Our battery benchmark uses PCMark for Android’s Work 3.0 Battery Life test to determine a modern Android-based smartphone's battery uptime in minutes. This controlled benchmark simulates real-world usage with a combination of both web and social media browsing, video and photo editing, parsing data with various file formats, writing (on documents), and more.

The Xiaomi 15 Ultra has a 5,410mAh silicon-carbon battery, 8.2% more capacity than its predecessor. While its tested battery life is an hour and 18 minutes less than Samsung’s Galaxy S25 Ultra, lasting nearly 14 hours is well within expectations of premium flagship handsets. 

It’s also 100 minutes longer than its predecessor, which means that the generational leaps you see above did not come at a huge cost to battery life, and the extra 410mAh does help meet users' needs for a phone that’s bigger, longer, faster, and all-around better.

While Singapore’s in-retail sets of Xiaomi 15 Ultra include a charging adapter, our review unit did not. Our charging experience relied on other modern third-party fast chargers we had lying about, which could comfortably get 0-100% in 70–80 minutes. Still, we’d have preferred trying out Xiaomi’s 120W charger instead.

The phone also offered 80W wireless charging, which is expected for premium handsets. 

A contribution by one of our HWZ Forum moderators using a Xiaomi 15 Ultra replicated our charging tests and scored 66 minutes with Xiaomi's included 120W charger, which is on par with our third-party charging experience.

Conclusion

We contend that Xiaomi 15 Ultra is a viable premium handset worthy of its S$1,699 (512GB) sticker price, but that’s relative to other premium flagship phones launched in 2025. 

It checks all the boxes as a well-rounded premium device from an Ultra perspective. You’re getting an excellent, high-resolution display capable of smooth visuals and accurate response, paired with one of the best mobile processors you can buy in 2025. The battery life is fantastic. It also has a set of cameras that can turn a hopeless photographer who can’t tell his subject apart from his finger in the frame, into a semi-decent shooter.

Even its HyperOS 2 interface is starting to measure up to rivalling operating system reskins with more logical flow and user intuitiveness, save for a few hiccups that will require little more than rearranging and attention to detail.

If we’re talking about mass appeal, it looks like Xiaomi 15 Ultra has it. Phones are supposed to work for their users, not the other way around, and Xiaomi showed they understood the assignment. 

Even when compared to its competition here, Xiaomi 15 Ultra puts up a good fight.

Honor Magic7 Pro (S$1,399 for 512GB) may be the most affordable rival, but it lacks the UI polish, camera prowess, or self-made AI tricks (that work). It’s comparable in battery life, so it’s a toss-up between paying S$300 more for Xiaomi's additional perks or Honor’s comparable alternative.

Over to the Samsung Galaxy S25 Ultra (S$1,828 for 256GB), you’re paying more money for half the storage if you go with the Koreans. Essential functions are also easily achieved with Xiaomi 15 Ultra, with the latter also showing up through good telephoto, Gemini perks, a fantastic display, and high battery life. If anything, Xiaomi got a leg up because Samsung decidedly crippled their unique stylus for not much in return.

If anything, we’d think it only has to worry about the OPPO Find X8 Pro (S$1,649 for 512GB). The OPPO premium flagship trounces the Xiaomi 15 Ultra in imaging performance and battery life, with a slightly lower price tag and a better design. If you're not hung up on having Qualcomm chips (like a normal person), then that makes both Chinese phones neck-to-neck in overall value and appeal.

These four phones are generally excellent devices, so it comes down to personal preference if you want to upgrade to Xiaomi 15 Ultra. Sure, the HyperAI features feel a little underwhelming, but we can see where Xiaomi’s head is, and we think the company can develop sound and useful AI features if they try.

If you’re coming from an older Xiaomi 14 Ultra, we think the generational refinements in Xiaomi 15 Ultra help justify its renewal. Xiaomi did try to add more to an already Ultra device in slightly meaningful (but not game-changing) ways.

By right, it’s more fiscally responsible to say you can continue using the previous phone until it gives up the ghost. When it finally does, you will have an even nicer Xiaomi 15 Ultra waiting ahead.

Hopefully, the brand will figure out how to make Ultra less bulky with mind-blowing AI tools in the next iteration, but that’s for future Xiaomi to worry about.

The Xiaomi 15 Ultra officially retails at S$1,699 (16GB RAM and 512GB storage) on Xiaomi’s official online store and official platforms like Shopee and Lazada. The full pricing article is here.