I tested the two best Android flagship phones of 2025 - and the winner is not so obvious
Which phone deserves your hard-earned money going into 2026, the Samsung Galaxy S25 Ultra or the OnePlus 15? Here's my verdict.
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OnePlus is ending 2025 with a bang. The OnePlus 15 has arrived early, and it takes on the heavyweights like Samsung Galaxy S25 Ultra without costing a thousand dollars (unless you configure it with more storage and RAM). It offers a big and bright display, the latest Qualcomm flagship processor, a huge battery, and much more.
So, should anyone buy the Galaxy S25 Ultra in today's market? It turns out, there are still several reasons to spring for Samsung's flagship, even if OnePlus is the new hotness.
Also: Thousands of readers bought these phones in 2025, but none of us expected no. 1
If you are undecided between the two phones or just want to compare the latest OnePlus 15 to the Galaxy S25 Ultra, you're in the right place. I compared the two flagships below, and here's the one that'll better suit your needs.
You should buy the OnePlus 15 if…
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1. You want a more durable phone
The OnePlus 15 is IP68 and IP69 rated for dust and water resistance, whereas the Galaxy S25 Ultra offers an IP68 rating. For the unaware, IP68 is for submersion, while the latter is for water jets at temperatures up to 80°C, ensuring the device can withstand even more extreme conditions. These are more important in day-to-day use, thanks to a screen that can withstand water droplets.
You can't use a Samsung or Apple phone's screen in a drizzle or around the pool because the water droplets register fake touches. I could be replying to a text message and have to wipe off the screen consistently to get my message right. By contrast, the OnePlus 15's display allows you to interact with the screen even when it's covered in water droplets. This means I can change songs in the shower and text a friend near a pool without worrying about water getting inside the phone or interfering with my screen.
If you opt for the Sand Storm variant, you get a more durable frame. According to OnePlus, this "MAO-treated middle frame" offers better durability than other variants -- making the OnePlus 15 more durable for daily use than the Galaxy S25 Ultra.
2. You need your phone to last more than a day
The OnePlus 15 features a 7,300mAh battery capacity, which reportedly incorporates 15% silicon content in the anode for enhanced energy density (compared to the industry standard of 10% silicon content currently in use). By comparison, the Galaxy S25 Ultra sports an ageing 5,000mAh battery capacity. In my usage, both these phones lasted longer than I expected, but that's because I kept my expectations low when using the Samsung flagship.
Also: Forget Samsung S25 Ultra: This OnePlus flagship beats the Android giant in meaningful ways
I've been using the OnePlus 15 for a week now. Yesterday, I began my day at 8 a.m. to go to a conference. I used social media apps like WhatsApp, Instagram, captured a lot of photos using the default Camera app, navigated using Maps, and listened to music on Spotify. By dinner time, I had 40% battery left on my phone.
The Galaxy S25 Ultra wouldn't last me through the evening on days like these with heavy usage. On the OnePlus 15, I've consistently clocked nine hours of screen time and still had plenty of battery left for doomscrolling before bed. If you want your phone to easily last you a day and go up to two days on moderate usage, the OnePlus 15 is your best bet. And when you are low on battery, it'll also charge faster at 80W, as compared to Samsung's 45W fast charging.
3. $200 in savings sounds good to you
The OnePlus 15 is powered by the Qualcomm Snapdragon 8 Elite Gen 5 chipset, as compared to last year's Snapdragon 8 Elite on the Galaxy S25 Ultra. OnePlus has paired it with a 1.5K resolution and 165Hz refresh rate-supported display alongside a large vapor cooling system. It is arguably more powerful than the Samsung flagship without breaking the bank.
If you are fond of mobile games but don't want to spend more than $1,000 to get the most powerful flagship phone on the market, the OnePlus 15 would serve you well. It is priced at $899 for the base variant, as compared to the Galaxy S25 Ultra's launch price of $1,300.
You should buy the Samsung Galaxy S25 Ultra if…
Prakhar Khanna/ZDNET
1. You want the best display on a phone
The Samsung Galaxy S25 Ultra builds upon the already class-leading Galaxy S24 Ultra display. It added a better anti-reflective coating to offer a more color-accurate display. This improves screen legibility in both indoor lighting and direct sunlight. It's a pleasing screen for consuming content, reading, and browsing the web. In fact, the Galaxy S25 Ultra has my favorite display on any smartphone I've used so far.
Also: Why the Samsung S25 Ultra is still my favorite Android phone this year - especially at this price
In comparison, the OnePlus 15 features a lower-resolution display and lacks an anti-reflective coating. It is still big and bright with narrower bezels, but it doesn't have the same pleasing-to-look-at experience. I'd love for Samsung to borrow OnePlus' AquaTouch technology for better usability in certain environments. That said, I'd pick the Galaxy S25 Ultra over OnePlus' new flagship phone for content consumption any day.
2. An S Pen stylus intrigues you
Samsung has repositioned the S Pen over the years -- moving it from the Note lineup to the Galaxy S series. It removed certain Bluetooth capabilities from the Galaxy S25 this year. However, it is still excellent for jotting down quick ideas and notes on your phone.
If you prefer writing on your phone's screen, the Galaxy S25 Ultra is the only high-end phone to offer this feature. Remember, you no longer get features like a remote camera shutter button, but it still comes in handy at meetings. In contrast, the OnePlus 15 lacks this capability.
3. You want longer software support
OnePlus is offering four years of OS support and five years of security updates with the new OnePlus 15. It runs Android 16 out of the box. In comparison, the Galaxy S25 Ultra was launched with Android 15-based One UI 7 and received its first OS upgrade a couple of months ago.
Also: The best Samsung phones of 2025
Despite that, it will last you longer than the OnePlus 15 -- Samsung offers seven years of OS and security updates. If you buy the Galaxy S25 Ultra right now, it will last you one year longer than the OnePlus 15, provided you're fine with the overtime degradation in battery life.
Specifications
OnePlus 15
Samsung Galaxy S25 Ultra
Display
6.78" AMOLED with 165Hz, 1800 nits peak
6.9" QHD AMOLED 120Hz, 2600 nits peak
Weight
211 grams (Sand Storm), 215 grams (Infinie Black / Ultra Violet)
218 grams
Processor
Qualcomm Snapdragon 8 Elite Gen 5
Qualcomm Snapdragon 8 Elite for Galaxy
Dimensions
76.7 x 161.4 x 8.1mm
77.6 x 162.8 x 8.2mm
Storage
256GB, 512GB
256GB, 512GB, 1TB
Battery
7,300mAh, 80W wired fast charging and 50W wireless charging
5,000mAh, 45W wired charging and 15W wireless charging
Camera
50MP wide / 50MP Ultra Wide / 50MP telephoto (3.5x) / 32MP front
200MP wide / 50MP telephoto (5x) / 10MP telephoto (3x) / 50 MP ultrawide / 12MP front
Price
$899
$1,299 (when not on sale)