Announced at MWC 2025, the Xiaomi 15 Ultra is Xiaomi’s new camera-focused flagship. But how does it compare to the Samsung Galaxy S25 Ultra, one of the most popular camera phones around?
While both are clearly vying for a spot in our best camera phone chart, the two ultra-flagships differ in various ways, from AI smarts to battery life and charging, which could influence your buying decision.
Here’s how the Xiaomi 15 Ultra stacks up against the Samsung Galaxy S25 Ultra based on specs.
Pricing & availability
The Xiaomi 15 Ultra was unveiled at MWC 2025 and will soon be available in the UK for a not-insignificant £1,299. It has 512GB of storage and will be available from retailers like Amazon.
The Samsung Galaxy S25 Ultra is slightly cheaper, at £1,249, and has 256GB of storage. It launched in January 2025 and is now readily available at retailers worldwide.
The Xiaomi 15 Ultra has more capable camera hardware
Both the Samsung Galaxy S25 Ultra and Xiaomi 15 Ultra have a particular focus on camera capabilities, and the competition between the two is fierce.
For starters, both have a combination of a main, ultrawide, telephoto and periscope lens, though the approach to camera hardware is vastly different elsewhere.
The Samsung Galaxy S25 Ultra packs a high-res 200MP main camera alongside a 48MP ultrawide, a 10MP 3x telephoto lens, and a 50MP 5x periscope lens, the latter of which can enable up to 100x digital zoom.
The Xiaomi 15 Ultra, on the other hand, offers a 50MP main camera, 50MP ultrawide, 50MP 3x telephoto, and 200MP 4.8x periscope. The periscope lens is one of the biggest upgrades this year, boosting the phone’s digital zoom capabilities.
It’s not just about megapixel count, though. It’s worth noting that Xiaomi uses larger sensors than Samsung in most of its lenses, including a huge 1-inch sensor powering the 50MP f/1.68 main lens. The phone also has a floating telephoto camera design for boosted stabilisation and macro capabilities.
Oh, and like previous Xiaomi phones, it also features Leica-branded shooting modes and filters that resemble the brand’s most popular cameras.
The proof will be in the cameras’ performance, of course – something we’ll test for the full comparison coming soon.
The Samsung Galaxy S25 Ultra has Galaxy AI
Artificial intelligence is the big thing when it comes to flagship smartphones in 2025, so much so that most of Samsung’s S25 announcement focused on new AI features rather than hardware. Some might say that’s because the hardware is very similar, and those people might be correct, but that doesn’t change the fact that phone manufacturers are going all in on AI.
That said, Samsung is leading the pack in the Android world with its swathe of genAI-powered features under the Galaxy AI umbrella. These features range from handy features like rewriting messages in a different style or removing people from images to more powerful capabilities like generating new images based only on text and much more.
New additions for the 2025 flagship also include the Now Brief, which aims to summarise information from various apps and resources in one place, and a smarter Gemini that can perform multi-app actions.
That’s not to say Xiaomi hasn’t worked its AI-themed magic with the Xiaomi 15 Ultra, however. The competing flagship also has a range of AI features including an alternative to Samsung’s text rewriting feature, on-device transcription and translation capabilities and even AI-powered image expansion tech.
It also features the ever-popular Google Circle to Search, and for the hard of hearing, it’ll automatically generate on-screen subtitles for videos.
It’s a healthy offering, but it’s not quite as expansive and feature-packed as the Galaxy S25 Ultra.
The Xiaomi 15 Ultra has a bigger battery and faster charging
When it comes to battery life, neither smartphone should struggle to get you through a day’s use – though with a larger battery found within, the Xiaomi 15 Ultra should last slightly longer than the Galaxy S25 Ultra.
That said, there’s not a world of a difference when it comes to the milliamp hour count, with the Galaxy S25 Ultra clocking in with the same 5000mAh cell as its predecessor while the Xiaomi competitor offers a 5410mAh cell.
The difference is much more significant in some regions, with the 15 Ultra shipping with an even larger 6000mAh cell – but we don’t get that in the UK or Europe.
Xiaomi also beats Samsung in the charging department. The Xiaomi 15 Ultra packs 90W HyperCharge support and 80W wireless charging, compared to 45W wired and 15W wireless charging from the S25 Ultra.
However, you need a proprietary Xiaomi charger to achieve those speeds, while the Ultra’s 45W can be achieved by any sufficiently powerful USB-C charger.
The Samsung Galaxy S25 Ultra has a longer software promise
The Samsung Galaxy S25 Ultra comes with Samsung’s OneUI 7 based on Android 15 out of the box, while the Xiaomi 15 Ultra comes with Xiaomi’s HyperOS 2 based on Android 15.
Neither of these UIs are close to what we’d describe as stock Android. Both offer their own respective spins on the Android experience with customised UI elements, additional features and more.
Traditionally, OneUI has offered a sleeker experience than Xiaomi’s rather bloated MIUI, but with the rebranded HyperOS, the company has cleaned things up somewhat. However, whether this will make the experience more manageable for Western users is yet to be seen.
Regardless of OS style, the Samsung Galaxy S25 Ultra will get more OS upgrades than the Xiaomi 15 Ultra. That’s mainly due to Samsung’s commitment to seven years of OS upgrades, which is one of the best in the industry.
Xiaomi’s combination of four OS upgrades and five years of security updates isn’t quite up to scratch in comparison.
The Samsung Galaxy S25 Ultra has a nicer display
Though their overall specs are pretty similar, Samsung’s Galaxy S25 Ultra has a few extra niceties that make it slightly more tempting than Xiaomi’s 15 Ultra.
The Samsung Galaxy S25 Ultra sports a 6.9-inch AMOLED screen with an LTPO-enabled 120Hz refresh rate and, with a QHD+ resolution, it’s safe to say it’s pixel-packed. Aside from being slightly smaller at 6.73 inches, the Xiaomi 15 Ultra offers identical specs.
However, look a little closer and the two begin to pull away from one another. The S25 Ultra has a completely flat screen while Xiaomi continues to employ a quad-curved screen. Which you like will largely come down to personal preference, but the flat screen does negate those accidental taps you tend to get with curved screen displays.
The S25 Ultra also has way thinner bezels than the Xiaomi 15 Ultra – surprising given the ultra-slim 1.38mm-thick bezels of the regular Xiaomi 15. The Galaxy’s anti-reflective coating is also a big bonus compared to Xiaomi’s screen, which should negate reflections way better in bright environments.
Xiaomi’s screen does have some advantages: It offers a brighter peak brightness at 3200 nits and supports Dolby Vision HDR – areas where Samsung’s flagship is noticeably lacking. Overall, however, Samsung might have the edge in the screen department.
Early Thoughts
Both the Xiaomi 15 Ultra and Samsung Galaxy S25 Ultra are high-end smartphones with specifications to match – although it seems that Xiaomi may hold the advantage in the crucial camera department, boasting larger, higher-resolution sensors compared to Samsung’s offering. Additionally, it features a larger battery and quicker charging than Samsung’s option.
However, the Samsung Galaxy S25 Ultra has plenty to appreciate, including its 6.9-inch ani-reflective OLED screen, Galaxy AI smarts, and industry-leading software promise. It’s a tough call, but one we’ll wait on delivering until we’ve spent more time with the Xiaomi 15 Ultra. Check back soon for our final verdict.
