Zenfone 12 Ultra vs Galaxy S25 Ultra: one of these is not an Ultra

Now, the Zenfone 12 Ultra follows suit, housed in the same chassis — quite literally, as its shape, size, and build remain unchanged, with only minor design tweaks and, of course, upgraded internals. It’s as big as the Galaxy S25 Ultra and obviously aims at the same target audience.But does it bring the heat? Can the Zenfone 12 Ultra hold a candle to Samsung’s immaculate flagship for 2025? Let’s go in deep:

Zenfone 12 Ultra vs Galaxy S25 Ultra differences explained:

Very similar internals, indeed. It bears mention that the Zenfone 12 Ultra will only be available in the 16 GB / 512 GB option in most markets. And none of its variants are going to make it to the USA this year.

Zenfone 12 Ultra vs Galaxy S25 Ultra: PhoneArena Review Ratings compared

Table of Contents:

We’re not sparing the Galaxy S25 Ultra‘s camera module here. Although it exudes confidence with its huge lens rings, those are just tacked-on there. The lenses are not bigger, they are about the same as an S24 Ultra, it’s just that Samsung made the decision to have these huge floating rings on the Galaxy S25 Ultra‘s back. Perfect lint-collectors, for sure!

But as an overall package, the Galaxy S25 Ultra does look better. It’s also more fun to hold with its new flat sides and titanium finishes.

The Zenfone 12 Ultra is available in three colors: Ebony Black, Sage Green, and Sakura White (it’s pink, despite the name). The Galaxy S25 Ultra appears more fun to shop for, as it comes in four standard colors — Titanium Black, Gray, Silverblue, and Whitesilver — plus three exclusive Samsung.com colors, which are Titanium Jadegreen, Jetblack, and Pinkgold. But none of them are vibrant or popping in any way, Samsung maintains the standard that expensive flagships should have a bit of a more grounded and “serious” look.

They weigh about the same at 220 g vs 218 g, for the Zenfone and Galaxy, respectfully. They also measure similarly at 163.8 x 77 x 8.9 mm vs 162.8 x 77.6 x 8.2 mm.

The Samsung has a slightly larger display, thanks to its new thin bezels. The S25 Ultra now has a 6.9-inch panel, where the Zenfone 12 Ultra has a 6.78-inch one. Both are AMOLED tech, and both are actually made by Samsung. They are LTPO panels with a dynamic refresh rate of 1-120 Hz. The Zenfone can, technically, hit 144 Hz, but that’s only available while gaming, from the Game Genie overlay.

Display Measurements:

Both phones also have multiple options to tame the color calibration as you like. Or let it glow with full vibrancy if you so wish. The Zenfone 12 Ultra is rated for 2,500 nits peak brightness, the Galaxy S25 Ultra — 2,600 nits. But we do measure 20% APL, which is more representative of “real world” use. Both phones comfortably go beyond 2,000 nits, which is plenty bright, so excellent results. Where the Galaxy S25 Ultra is a clear winner is with minimum brightness. It can go below 1 nit, which is great for nighttime viewing, whereas the Zenfone 12 Ultra can’t go below 5.9 nits — not an ideal bedside companion.Additionally, Samsung has an excellent anti-glare coating on top of its Ultra phones, which does make a huge difference and makes the image “pop” more, either indoors, or under daylight.

The Zenfone 12 Ultra is meant to be a contemporary flagship, so it gets the big-name chip — the 3 nm Qualcomm Snapdragon 8 Elite. But Samsung has a partnership with Qualcomm, so it gets a special Snapdragon 8 Elite for Galaxy edition. Basically, it’s slightly overclocked, hitting 4.47 GHz where “ordinary” Elites go up to 4.32 GHz. Aside from that, both phones come with the fastest memory chips — LPDDR5X and UFS4.0.

So, on to the benchmarks!

Performance Benchmarks:

The software here is Android 15 on both phones. Zenfone 12 Ultra dresses it up in ZenUI, which looks like Vanilla Android, but adds a couple of custom features on top. Of course, this year, the word is AI. The Zenfone 12 Ultra now also has AI summary for websites and documents, live translation for voice calls, transcription of voice recordings, Google’s Circle to Search, a Magic Eraser in Photos (called AI Magic Fill), and Photo Unblur. These features are also present in Galaxy AI or provided by Google via Gemini or the Photos app.

Camera

Does a gimbal stabilizer stand a chance against Samsung’s powerhouse?

Asus’ selling point for its camera modules is a gimbal stabilizer. It’s slightly upgraded this year, supposedly to reduce jitters in video and blurry pictures even more. But we can hardly complain about Samsung’s stabilization. And Samsung puts a lot of eggs in the camera basket, with a total of 4 cameras on the back (two are for zooming), and a lot of software features in the app. Plus, it’s image processing is just… better.

Video quality

The gimbal stabilizer of the Zenfone 12 Ultra does give us very buttery smooth motion, but the Galaxy S25 Ultra seems to be doing plenty fine with its own OIS and software assistance. The colors from the Zenfone footage are more vibrant, but details are a bit oversharpened, and some halos around vegetation can be spotted — probably HDR. The Galaxy S25 Ultra footage is more balanced, but it does look a bit colder in this direct comparison. However, it handles highlights a bit better where the Zenfone burned them out. And the green grass looks a bit more realistic, which is something Samsung hasn’t always been the best at!

Battery Life and Charging

Large phones, large batteries

The Zenfone 12 Ultra comes with a 5,500 mAh battery, while Samsung is still not comfortable in pushing the envelope so it sticks to 5,000 mAh. It’s interesting to see how the identical chipsets with fairly similar screens will fare. Is it all in the software optimization? Here’s how our battery test went:

PhoneArena Battery and Charging Test Results:

When it comes to charging, the Zenfone 12 Ultra is faster, thanks to supporting a 65 W charger. The Galaxy S24 Ultra tops out at 45 W on the wire, but does support up to 15 W wirelessly, so does the Zenfone.

Now that we’ve gone through all the tests, let’s get a final reminder of the Zenfone 12 Ultra vs Galaxy S25 Ultra specs, the abbreviated version:

All of that said, Asus still wants to sell it for €1,099 (512 GB version) in Europe, where the Galaxy S25 Ultra starts at €1,470. Clearly, that’s quite the uptick in price, but even a Galaxy S25+ will do better and serve you longer (or it should) than the Zenfone 12 Ultra. Sorry, as much as we like what Asus usually does, this phone is not exactly it.