I compared the two best Android flagship phones right now - and it got really complicated

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OnePlus ended last year on a high note. The OnePlus 15 arrived earlier than expected, and it took on heavyweights like the Samsung Galaxy S25 Ultra without costing a thousand dollars (unless you configure it with more storage and RAM). The phone offered a compelling spec package, including a big, bright display, the latest Qualcomm flagship processor, a huge battery, and more. 

Now that the dust has settled, 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, and an S26 Ultra is on the horizon.

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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 is IP68 rated. 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.

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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 with 15% silicon content in the anode, reportedly for enhanced energy density (compared to the industry-standard 10% silicon content currently in use). By comparison, the Galaxy S25 Ultra features an ageing 5,000mAh battery. In my experience, both phones lasted longer than I expected, but that's because I kept my expectations low with the Samsung flagship.

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I've been using the OnePlus 15 for months now. Just yesterday, I started my day at 8 a.m. to attend a conference. I used social media apps like WhatsApp and Instagram, captured a lot of photos with the default Camera app, navigated with 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 the Snapdragon 8 Elite on the Galaxy S25 Ultra. OnePlus has paired it with a 1.5K-resolution, 165Hz-refresh-rate 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…

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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.

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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 offer the same pleasing-to-the-eye 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 last 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.

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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.

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