Galaxy S25 Ultra vs Xiaomi 15 Pro: A tough nut to crack

The Galaxy S25 Ultra is one of the most anticipated Android flagships of the next year, and even though its announcement date is still a mystery, we have tons of leaks and rumors about this impressive device.

On the other side of the comparison, or in the opposite corner, as they say in boxing, we have the contender, the Xiaomi 15 Pro. The main difference here is that this flagship is already official, albeit in China, for the moment.

This gives us all the necessary information, barring the actual tests, benchmarks, and camera samples, to try and assess the Xiaomi 15 Pro. Of course, this comparison is a preliminary one, based on the specs of the Chinese version of the Xiaomi 15 Pro and rumors about the yet-to-be-released Galaxy S25 Ultra, so bear this in mind.

Let's start with the overall design of the Galaxy S25 Ultra—or at least what we know so far. Samsung's next flagship remains shrouded in mystery, with only a few whispers about its design reaching the surface. Rumor has it that the S25 Ultra will sport a more rounded body, potentially making it the sleekest Ultra model yet.

While the overall aesthetic is likely to remain familiar—complete with separate rear camera modules and the signature S Pen slot—the subtle refinements aim to further streamline the design.

As for materials and durability, the S25 Ultra is expected to follow the trend of its predecessor. Continuing the titanium trend, we expect it to boast enhanced toughness, potentially paired with the latest generation of Gorilla Glass for superior protection against everyday wear and tear and the cool anti-glare coating from the previous generation.

Finally, we have some information about the expected Galaxy S25 Ultra colors:

• Black
• Green
• Blue
• Titanium

Now the Xiaomi 15 Pro is already official, and even though we don't know benchmark data, its design is out in the open. The phone sticks closely to the blueprint of its predecessor. It carries forward the same design language: flat edges, a flat front and back, and the familiar glass-and-metal sandwich construction. Even the square-shaped camera module on the back is unchanged.

In terms of size and weight, the phone will be a little more compact and lightweight, compared to the Galaxy S25 Ultra. Notably, unlike its predecessor, the Xiaomi 15 Pro skips the titanium variant this time around, which might disappoint some fans of the premium material and put the phone at a disadvantage, especially compared to the Galaxy S25 (like we're doing now).

As for colors, the Chinese launch unveiled the following options:

• Bright Silver Edition
• Rock Gray
• White
• Spruce Green

The display part of the equation looks more similar than different this time around. We expect the Galaxy S25 Ultra to feature a 6.8-inch display, maintaining its 2K 1440 x 3080 resolution. It’s set to include LTPO 3.0 technology, granting that smooth and sleek 1-120Hz refresh rate.

In terms of brightness, we do expect a bump, but the latest rumors say that the Galaxy S25 Ultra won't be using the M14 display material (that the iPhone 16 Pro Max has onboard), but stick to the M13 for cost-related reasons. We have to test the display to see if it makes a difference.

Last but not least, the ever-flattening curvature of smartphone displays these days will still be present on the Galaxy S25 Ultra, but it seems that the trend is to make every flagship phone display flat in 2025. We approve!

The specs of the Xiaomi 15 Pro's display are out, so we can compare them to the rumored specs of the S25 Ultra, at least until we test both phones in our lab. The device features a 6.73-inch 2K OLED curved display with a 3200 x 1440 resolution. It uses TCL CSOT’s advanced M9 luminous materials, and the company claims a peak brightness of 3,200 nits.

When it comes to biometrics, both phones feature ultrasonic under-display fingerpring scanners. The Galaxy S25 Ultra is expected to carry over this technology from its predecessor (no need to downgrade), and the Xiaomi 15 Pro received an upgrade from the optical sensor on the last gen.

While "Elite" puns are already getting old, it's still true that these two flagship phones are members of that club. They both feature a Snapdragon 8 Elite chipset, and the Galaxy S25 Ultra is expected to receive the slight overclock that goes with the "for Galaxy" branding of the Qualcomm chipsets of late.

Meanwhile, the Xiaomi 15 Pro appeared in a couple of Geekbench 6 sheets, showing impressive performance and aiming to take the crown from Apple's A18 Pro silicon. The battle between the Xiaomi 15 Pro and the Galaxy S25 Ultra will be fierce on the hardware front; stay tuned for our benchmarks and the winner.

In terms of RAM and storage, both phones feature the same configurations. The base option starts at 12GB of RAM and 256GB of onboard storage, while the top model comes with 16GB of RAM and 1TB of memory.

This section is nothing without side-by-side samples, and we will provide some as soon as we lay our techy hands on both devices. Meanwhile, we can take a look at the technical specs of the camera systems of both phones.

The Galaxy S25 Ultra is likely to retain the same camera setup as its predecessor, with one significant enhancement: the ultra-wide lens is expected to feature Samsung's new 50 MP Isocell JN3 sensor. With a pixel size of 0.7 micrometers, this upgrade promises sharper detail and better low-light performance, elevating the capabilities of the ultra-wide shooter.

The Xiaomi 15 Pro’s camera system features three 50 MP sensors across its setup, and they look rather familiar. The main camera boasts an f/1.44 aperture lens with a 23mm equivalent focal length, optical image stabilization (OIS), and 2.4μm quad-pixel technology.

The ultra-wide camera includes an f/2.2 aperture, a 14mm equivalent focal length, and a 5 cm macro distance. These are the same as what we had on the Xiaomi 14 Pro, but what's different is the telephoto camera. It's now a periscope system with a 120mm equivalent focal length, OIS, and an f/2.5 aperture.

Now, when it comes to battery and charging, Chinese manufacturers are much more keen to innovate, mainly due to the more loose regulations in the country. The Xiaomi 15 Pro is a prime example. The phone comes with a silicon-carbon battery, providing increased capacity thanks to the silicon imbued in the graphene anode.

This technology first came out of China in the form of the Honor Magic 6 Pro, but now more and more flagship models are hopping on that train, OnePlus 13 included. Back to the Xiaomi 15 Pro, the phone features a monstrous 6,100 mAh battery, one of the largest for a phone of this size. The fast charging is also pretty fast, at least on paper. The phone supports 90W wired and 50W wireless.

The Galaxy S25 Ultra, on the other hand, treats this category much more conservatively, or at least that's what we can gather from leaks and rumors. The phone is likely to retain the same battery capacity and charging speeds as its predecessor, which might disappoint some Samsung fans. Current specs suggest 45W wired charging and 15W wireless charging, though rumors hint at a possible upgrade to 25W wireless support.

Our battery and charging benchmarks and widgets will show the true differences, so stay tuned for some hard numbers soon.

This comparison is yet to bloom into a full-fledged article with benchmarks, camera samples, and battery tests. But judging from the specs and our preliminary info, the Xiaomi 15 Pro will have a hard time competing with the Galaxy S25 Ultra.

The latter comes with its signature S Pen, a flatter screen, and the overclocked version of the Snapdragon 8 Elite. Couple all this with the extra telephoto camera, and you have a winner. 

On the other hand, the Xiaomi 15 Pro impresses with its huge battery and fast charging, so the final verdict is still unclear. The global pricing will also impact this comparison greatly, so stay tuned for the final version when we finish reviewing both phones.