Xiaomi 15 Ultra review

Android 15 and HyperOS 2

The Xiaomi 15 Ultra runs Android 15, augmented by the company's latest HyperOS 2.0 (.2, even). Xiaomi has promised that 4 future OS releases will make it to the phone, and it should be covered with security patches for a total of 6 years.

As usual, there's some nice continuity between versions and HyperOS 2 will be quite familiar if you've come across a HyperOS 1 device or a Xiaomi from the MIUI times. Naturally, there's some extra polish now, plus neat AI tricks, and Xiaomi claims under-the-hood optimizations as well.

HyperOS 2.0 on the Xiaomi 15 Ultra

Our Xiaomi 15 Ultra gives you the option for an app drawer, but you can also choose to have everything on the homescreens. Some software branches don't let you have the app drawer, but we appreciate seeing that option here. A third "light" UX option that makes icons bigger and things a bit more accessible is also on the menu.

HyperOS 2 has separate Notifications and Control center pages with no option for a joint interface for the two. The homescreens support apps and widgets, as well as two flavors of large folders. The -1 homescreen can only be Google Discover - App Vault by Xiaomi seems to be gone in this version of the OS.

More HyperOS 2.0

Then there's the AI functionality, of which there's plenty on the Xiaomi 15 Ultra.

Sure enough, there's Google Gemini. You can ask Gemini a lot of stuff to do and even make entire conversations. You can also have it create images for you. Circle to Search is available system-wide as well.

Gemini • Gemini • Circle to Search

Beyond the generic Gemini stuff, there are plenty of in-house AI features. Xiaomi does a good job of organizing these in a menu in Settings for explanation purposes. You still have to access the features themselves from their respective apps and locations, but it is very convenient to actually have a central location where everything is nicely laid out.

AI stuff

The Notes app can transform text in many ways. You can do translation, proofreading, summary and AI layout. The gallery app can do object deletion as well as generation for the sake of background expansion and similar tasks. You can even generate a short video from a static image. The Recorder app can do automatic transcription with speaker detection and separation, and you can translate the transcriptions. You can enable system-wide AI subtitles for multimedia consumption. There is also an AI interpreter that can do both face-to-face translation and call translation.

More AI stuff

There's a whole lot of AI based image editing features in the gallery. There's an object/people remover, you can remove reflections, do content-aware expansion, or change how the sky looks in your shots.

AI image editing features

You mileage will vary, naturally, but we did a quick try of a few of the features, and here's how they came out.

Object eraser: Before • After | Expand: Before • After

Sky: Before • After

It is worth noting that despite the vast power available from the Snapdragon 8 Elite chipset, many of Xiaomi's AI features are still cloud-based. Xiaomi isn't charging for anything, at least for now.

Performance and benchmarks

The Xiaomi 15 Ultra is on the Elite branch of Android flagships this year - it's using the Qualcomm high-end chip as opposed to the Dimensity we're getting from some Chinese competitors. The Snapdragon 8 Elite is a known quantity, of course, already featured in the Galaxy S25s and a number of other top-shelf handsets from recent weeks and months.

The 15 Ultra exists in a number of memory configurations in China, though the world is likely only getting two - the 16GB/512GB version we reviewed or a 16GB/1TB spec. RAM is LPDDR5X and storage is UFS 4.1 which is just like UFS 4.0 (so - fast), but with hard to quantify 0.1 improvements on top.

The 15 Ultra posted fairly predictable numbers in benchmarks. It ranks in the middle of the pack of the Elites - no standout numbers one way or the other.

It's a bit more of a rocky ride in the sustained load benchmarks. The 15 Ultra wouldn't complete a 3DMark Wild Life Extreme stress test - not in Performance mode, and not in the regular Balanced mode - it called it quits at the 19th or 20th 1-minute run of the 20-minute benchmark. In the CPU Throttling test, we got a 60% overall result and a somewhat unusual graph with a relatively small performance decline in the early stages and a more substantial drop later on, accompanied with a fine-tooth comb behavior. We've seen better, we've seen worse.

CPU Throttling test