Samsung Galaxy S26 Ultra vs OnePlus 15: Main differences

Samsung has just announced the Galaxy S26 Ultra, its top flagship for 2026, and it's very similar to the Galaxy S25 Ultra with just a few key improvements here and there, but nothing too drastic.

The key new feature here is the new Privacy screen feature, which obscures your sensitive data from prying eyes. The phone also features the Snapdragon 8 Elite Gen 5, the fastest chip for Android devices right now.

In terms of rivals, there are a few already, like the iPhone 17 Pro Max and the Pixel 10 Pro XL, but another one is the OnePlus 15.

It is powered by the same chipset but has a much larger battery that no Samsung flagship will get anytime soon (aside from the company's tablets, and that's saying something). 

In this article, we will summarize what we know of these two Android darlings and compare their ins and outs with the goal of determining which one is the smarter buy in 2026. Flagship battle, commence!

Pre-order the Galaxy S26 for up to $500 off

$399 ⁹⁹

$899 ⁹⁹

$500 off (56%)

The "vanilla" Galaxy S26 has finally been announced. With a next-gen Galaxy AI and a powerful chip, this phone checks all the boxes. Right now, you can pre-order the phone for up to $500 with trade-ins.

Pre-order at Samsung

Pre-order the Galaxy S26+ for up to $700 off

$399 ⁹⁹

$1099 ⁹⁹

$700 off (64%)

The Galaxy S26+ is here, bringing improved software and a more powerful processor. The device can now be available for up to $700 off at the official store with eligible device trade-ins.

Pre-order at Samsung

Pre-order the Galaxy S26 Ultra for up to $900 off

$399 ⁹⁹

$1299 ⁹⁹

$900 off (69%)

The Galaxy S26 Ultra has been announced, bringing a Privacy Screen feature, insanely fast processor, and multiple Galaxy AI enhancements. Right now, you can pre-order the flagship for up to $900 off with eligible trade-ins.

Pre-order at Samsung

OnePlus 15

6.8-inch

Triple camera

7300 mAh

12GB

$1049 at eBay

The Galaxy S26 Ultra has not scored any major design changes and looks mostly similar to the Galaxy S25 Ultra, with curved corners and a flat frame. The latter is made of aluminum, though, as Samsung is bidding goodbye to titanium. You could trace the reason for that shift to Apple, which changed the build materials with the iPhone 17 Pro and Pro Max. 

Meanwhile, the OnePlus 15 takes a lot of design inspiration from the Oppo Find X9 Pro. It utilizes a flat aluminum frame with a matte glass back. In terms of sizes, the OnePlus 15 is slightly more compact in terms of height and width and is only marginally thicker. Very curious, as the OnePlus 15 has a much more massive 7,300 mAh battery. With that in mind, a thickness of just over 8 millimeters is still mind-boggling.

In terms of water and dust resistance, the OnePlus 15 is the better-equipped device, as it will once again come with IP69-rated resistance. This one ensures protection against even strong water jets and pulses, certainly giving peace of mind. The Galaxy S26 Ultra is only IP68-rated. 

The Galaxy S26 Ultra could arrive in Black, White, Silver Shadow, Sky Blue, Cobalt Violet, and Pink Gold, while the OnePlus 15 comes in Infinite Black, Ultra Violet, and Sand Storm.

With the OnePlus 15, the display is getting a trim down to 6.78 inches, a minuscule difference against the OnePlus 13's 6.82-inch screen. We also get super-smooth 165Hz refresh rate support in some games, but in all other scenarios, the display runs at 120 Hz. 

The Galaxy S26 Ultra has Gorilla Glass Armor at the front, while the OnePlus 15 relies on the good ol' Gorilla Glass Victus 2.

At the same time, the Galaxy S26 Ultra display is very similar to the one on the Galaxy S25 Ultra. Think of a 6.9-inch size (among the largest around), with full HDR support, smooth 1-120Hz refresh rate support, and a lower peak brightness of 2,600 nits. There's a third-gen anti-reflective coating on board, which should passively boost the visibility. 

Now, in our display tests, the OnePlus dominates in terms of peak brightness, and by a mile at that. However, the Galaxy has it beat in terms of minimum brightness as well as color accuracy. 

Display Measurements:

Another upgrade is the new privacy film-like feature dubbed Privacy screen. This one protects any sensitive information on your screen from prying eyes around you. That's a pretty intriguing feature that could eliminate the need for a dedicated privacy screen protector.

Both the Galaxy S26 Ultra and the OnePlus 15 rely on ultrasonic fingerprint scanners. For your convenience, you will be able to add facial recognition as a possible unlock method, of course. 

Qualcomm is the chipset supplier for both the OnePlus 15 and the Galaxy S26 Ultra: the Snapdragon 8 Elite Gen 5 is ticking inside either one of these Android phones. In the case of the Galaxy S26 Ultra, this will be on a global scale, so we won't be getting an Exynos 2600 of the Ultra phone.

The Galaxy S26 Ultra comes with a new thermal interface material and a redesigned vapor chamber that's some 20% better at dissipating heat away from the chip. This enables the device to sustain its peak performance for longer before throttling.

Yet, the Samsung might have a leg up: it scores a Snapdragon 8 Elite Gen 5 for Galaxy chipset inside, a slightly overclocked version that will potentially deliver better raw performance than the one inside the OnePlus 15. Remains to be tested, though.

The Galaxy S26 Ultra also beats the OnePlus 15's Snapdragon 8 Elite Gen 5 in both the single- and multi-core Geekbench 6 tests, revealing that this year's "for Galaxy" chip is pretty tuned up. 

In terms of graphics performance, the Galaxy S26 Ultra achieves a significantly better peak graphics performance, but it is the first to throttle, while the OnePlus 15 sustains its peak graphics performance for longer. This speaks volumes about the thermal management of both phones, and… Samsung is beat here.  

The Galaxy S26 Ultra comes with 12 GB of RAM, a bit low for current Android flagships, which typically pack 16 GB of RAM these days. That's exactly what we get on the OnePlus 15, which packs 16 GB of memory for exceptional multitasking and future-proofness with AI in mind. You can get the Galaxy S26 Ultra with 16 GB of RAM, but only in the 1 TB storage version. 

Storage-wise, both phones start at 256 GB, but only the Galaxy S26 Ultra will be available with 1 TB of storage. The OnePlus 15 will only be available with up to 512 GB of storage. 

One UI 8.5 is the software of choice on the Galaxy S26 series, and besides seven years of software support, this one comes with many key new features, including important visual changes.

First, the software scores a new floating app bar at the bottom, which should improve the readability. Next up, One UI 8.5 now offers even more customization options and lets you personalize the Quick Settings panel even more by reordering and removing existing controls.

If you set a picture of a person or a pet as your lock screen wallpaper, the layout will automatically move around so that neither the clock nor the widgets obscure key parts of the image. There are a few extra customization options for the lock screen clock, too.

Galaxy AI has been upgraded with continuous image generation, which lets you generate several images without stopping and pick from the ones you want afterward.

Call Screening is another new feature that will let Galaxy AI answer calls for you and see who's calling and for what reason. You will be provided with a transcript and only then decide if you want to answer the call.

Bixby can now understand you better when you talk to the assistant in your own words. This lets you use it to find specific settings or features without having to sift through numerous menus. It now has an easy way of accessing your conversation history with Bixby.

The Galaxy S26 now comes with an AI-powered screenshot analyzer, which will automatically sort your screenshots into one of eight categories. You can then find these screenshots by simply searching for said category.

The Weather app has scored a more detailed new widget that will showcase a graph of any upcoming precipitation that is expected. Your daily alarms can also show the current weather as a background when they ring, which is a neat quality-of-life upgrade.

Samsung has also enhanced the battery info menu, making it easier to check the remaining battery life left, the battery usage, as well as your charging status. There are also two power-saving modes now: Standard, which is more temperate, and Maximum, which disables all non-essential features to boost battery life.

With the Galaxy S26 Ultra, we're getting the same camera setup as the one on the Galaxy S25 Ultra: a 200MP main camera, a 50MP ultrawide, and two zoom cameras, a 10MP 3X telephoto and a 50MP 5X periscope. So, any and all improvements will have to be on the software and image-processing side. 

The camera now comes with better image-processing and brighter apertures; letting more light in the camera is always welcome! There are also improvements to video stabilization: the phone uses real-time gyro and accelerometer data to keep horizons level and deliver smooth videos. The Galaxy S26 Ultra is also the first Galaxy to support the APV (Advanced Professional Video) format.

The OnePlus 15, on the other hand, has triple 50MP cameras, which perform well in our test but already lag behind the Galaxy S25 Ultra, which has scored a higher score in our test. Logically, we'd expect the Galaxy S26 Ultra to deepen the gap and take better photos and videos. 

Can you guess how many times Samsung has used a 5,000 mAh battery on its Galaxy S flagships? Let me save you from opening a new browser tab: it will be six times in a row once the Galaxy S26 Ultra arrives, as that one is also getting a 5,000 mAh battery, just like the very first Galaxy S20 Ultra. 

Not a particularly good outlook for Samsung given the recent developments in battery tech, where silicon-carbon batteries are now ruling the landscape and offer larger batteries than your standard lithium-ion battery.

The OnePlus 15 is shaping up to be one such exceptional example, as it's coming along with, drumroll please, a massive 7,300 mAh battery, significantly larger than what you'd get from any Galaxy flagship.

In terms of charging, the Galaxy S26 Ultra has scored a wired charging upgrade from 45W to 60W, which is a welcome and fantastic upgrade. 

Sadly, there's no magnetic attachments on deck that work similarly to Apple's MagSafe or Google's Pixelsnap. 

OnePlus, one of the leaders in terms of charging speeds, comes with 80 W fast charging and 50 W wireless charging. There's the proprietary wall adapter included in the box as well, which the Galaxy S26 Ultra doesn't.

Interestingly, those are double the charging speeds that the Galaxy S26 Ultra will likely end up with. 

Just like in previous years, OnePlus is set to bring the battle straight to Samsung with a phone that's shaping up to be a better value, all things considered.

The Galaxy S26 Ultra has scored some key improvements, like better performance, potentially improved camera, and faster charging, but it's all more of the same. Of course, the added benefit of the S Pen is also about to be part of the deal.

The OnePlus 15, on the other hand, gives us a raw upgrade in all key aspects that matter, including the performance, camera, and most importantly, the battery, which is set to be among the largest ones on a flagship device available in the US.