Is the newest the best for you? We compare the Xiaomi 17 Ultra against the Xiaomi 15 Ultra to see which is a better buy in 2026

There is a lot left to decide what is the best mobile phone of 2026but the new Xiaomi 17 Ultra He has all the ballots to be one of the candidates. The new top of the range from the Chinese manufacturer comes with changes compared to the previous Xiaomi 15 Ultra (the 16 does not exist, remember) and even with a launch offer. But, Is it worth paying more for the new model? We are going to analyze what the main differences between the two are to be able to decide more easily.

Differences between the Xiaomi 17 Ultra and Xiaomi 15 Ultra

The screen makes you fat, the body loses weight

Xiaomi, as Samsung has also done with their new Galaxy S26remains the same design, although refined. Xiaomi’s new mobile phone is its lightest and thinnest Ultra to datesomething quite impressive if we take into account the size of its battery (we will talk about that a little later).

There is a fairly important difference between the two: 9.4 millimeters thick and 226 grams of the 15 Ultra compared to 8.29 millimeters and 218 grams of its successor. That means that we are going to have orLess sensation of “huge” in handsomething that is appreciated if we take into account that it is a mobile that measures 16 centimeters high.

And the screen? In this case, it happens just the opposite: the Xiaomi 17 Ultra comes with a slightly larger 6.9-inch screen (compared to 6.73 for the 15 Ultra). This is how it is equal in inches compared to the Galaxy S26 Ultra. Beyond the size, it is also worth noting that the new Xiaomi also increases the maximum brightness level, ideal for those moments when we are on the street and the sun shines directly on the mobile.

More performance thanks to its new processor

At the hardware level, the expected improvement. Both phones have a Qualcomm processor: on the Xiaomi 15 Ultra’s side, the Snapdragon 8 Elite; of the new model, the Snapdragon 8 Elite Gen 5. We cannot talk about real figures because we have not tested the new Xiaomi phone, but with the data in hand, yes we can say that it will have better performance. At the end of the day, the new generation of Qualcomm’s processor is one of the best chips out there.

As far as memory is concerned, point for Xiaomi: Both phones start with 512 GB of storage and 16 GB of RAM. As an alternative, in both cases we have an additional configuration that increases the capacity up to 1 TB (although in exchange for paying 200 euros more).

There is a significant jump in battery size

The Xiaomi 15 Ultra arrived in Spain with a 5,410 mAh battery, different from the one the same mobile phone had in China (which was 6,000 mAh). Although it already offers great autonomy, the Xiaomi 17 Ultra wants to catapult it with a 6,000 mAh battery that this time we can enjoy. It is an important battery size, even more so if we take into account that the thickness of the mobile has been reduced.

And what about fast charging? There is no change there. Both devices have 90W fast wired charging and 50W wireless charging, so no matter which one you choose, you won’t find any difference in how fast your battery charges.

The main difference is in the cameras

One of the main strengths of the Xiaomi Ultra is in its cameras. The main camera, as with the 15 Ultra, is once again one inch, has 50 megapixels and is signed by Leica. A priori, there may not be much difference between their performance. Nor in the ultra wide angle, which is 50 megapixels in both cases. We cannot say the same about the telephoto lens.

The Xiaomi 15 Ultra came with two different 50-megapixel telephoto lenses. Simply put, the phone’s camera jumps from one to the other depending on the zoom distance we want to use when taking the photo. What happens with the new 17 Ultra? That this uses a single 200 megapixel sensor with variable aperture, so the zoom is continuous and does not hit those “jumps”. Therefore, the result is better.

Which one to choose from the two depending on what you are looking for or your needs

In which cases is the Xiaomi 17 Ultra worth the most?

The new top of the range comes with quite interesting improvements and changes, especially when it comes to battery and cameras. Now, as always, you have to weigh whether it is worth paying the price. The good news is that it comes out with a launch promo, so we now have it with a 250 euro discount. In that sense, this mobile is recommended if:

• You are looking to have a top of the range Xiaomi with the greatest possible autonomy.
• You want to have a more manageable mobile phone with a larger screen.
• You really like taking photos and you think you are going to put the improved telephoto lens to good use.

In which cases is the Xiaomi 15 Ultra worth the most?

In 2026, the Xiaomi 15 Ultra is still a very good phone. The problem here is that perhaps it is difficult to find it at a good price: the cheapest we have found has been at 1,179 eurosjust 70 euros less than what the Xiaomi 17 Ultra costs. At that price it is difficult to put it above, but things change if we look for it reconditioned or if we find it around 200 or 300 euros less. With a price like this, it would be recommended in case:

• Looking for a top photography experience without spending so much.
• You like big phones and you don’t mind that extra weight.
• You want a top-of-the-range Xiaomi mobile and you don’t mind looking at the previous generation.

And what happens with the base models?

This price difference that we talked about a few lines above is different in the case of the base models. The Xiaomi 17 part of the 899 euros in launch promo (its RRP is 999 euros), but the Xiaomi 15 is available from 699 euros. It’s 200 euros difference that are noticeable in your pocket and that may be worth saving if you are looking for a compact Xiaomi mobile.

What would you lose if you choose the Xiaomi 15? What stands out the most, without a doubt, is the battery: the Xiaomi 17 comes with 6,330 mAh, a huge difference with the 5,240 mAh of the Xiaomi 15. You would also have a screen with a little less maximum brightness, and a little less performance, mainly.

Technical sheet with the main differences between both Xiaomi phones

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Images | Xiaomi, Ricardo AguilarXataka

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