OnePlus 15 vs Galaxy S25 Ultra
Shopping across brands means comparing different philosophies. The OnePlus 15 and the Galaxy S25 Ultra show how OnePlus and Samsung each approach the flagship smartphone class. There’s no clean sweep. If display matters most to you, the OnePlus 15 has the edge; if memory & storage does, look at the Galaxy S25 Ultra. On top of that, the Galaxy S25 Ultra asked $400 more at launch.
At a glance
- Display OnePlus 15 wins
- Performance Tie
- Memory & Storage Galaxy S25 Ultra wins
- Camera Galaxy S25 Ultra wins
- Battery & Charging OnePlus 15 wins
- Software & Updates Galaxy S25 Ultra wins
- Price OnePlus 15 wins
- Display10.0
- Performance5.9
- Memory & Storage3.6
- Camera3.5
- Battery & Charging9.3
- Display6.8
- Performance5.9
- Memory & Storage4.5
- Camera5.5
- Battery & Charging2.8
Spec scores (0 to 10) are calculated from manufacturer specs against other models in the same class. See how the formula works. They are not reviews or user ratings.
Key Differences
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The Galaxy S25 Ultra has 3 years of extra promised updates
A clear win for the Galaxy S25 Ultra: 7 years against 4 years. Few specs in this matchup are as one-sided. The Galaxy S25 Ultra’s longer software support can also help its resale value later on.
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The OnePlus 15 has 46% more battery capacity
Here the OnePlus 15 pulls well ahead of the Galaxy S25 Ultra, with 7,300 mAh compared to 5,000 mAh. Extra capacity also ages better: after a few years of charge cycles, the OnePlus 15 has more headroom left.
-
The Galaxy S25 Ultra has 5× optical zoom versus 3.5×
The Galaxy S25 Ultra doesn’t just edge this one; 5× against 3.5× is a lead you’ll feel. Digital zoom can fake reach, but optical zoom is where the detail actually comes from.
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The OnePlus 15 has a 165 Hz display instead of 120 Hz
Big gap, real consequences. The OnePlus 15’s 165 Hz versus the Galaxy S25 Ultra’s 120 Hz changes how the two compare in daily use. A higher refresh rate makes scrolling, animations and games look smoother. Once you’re used to it, a lower-rate screen can feel sluggish by comparison.
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The Galaxy S25 Ultra has a higher-resolution 200 MP main camera
The OnePlus 15 is clearly behind on main camera (50 MP against 200 MP), and that’s one of its biggest weak spots in this matchup. Megapixels are only one part of image quality, so treat this as a sign of detail potential, not a verdict on photos.
Design & Size
- OnePlus 15 6.35 in × 3.02 in × 0.32 in
- Galaxy S25 Ultra 6.41 in × 3.06 in × 0.32 in
On overall dimensions, the OnePlus 15 and the Galaxy S25 Ultra are separated by very little. Their weights are close enough to treat as identical in daily use.
Design & Build
| Spec | OnePlus 15 | Galaxy S25 Ultra |
|---|---|---|
| Height | 6.35 in | 6.41 in |
| Width | 3.02 in | 3.06 in |
| Thickness | 0.32 in | 0.32 in |
| Weight | 7.44 oz | 7.69 oz |
| Water & dust rating | IP68/IP69 (winner) | IP68 |
| Frame | Aluminum | Titanium |
Display
OnePlus 15 leads
Here the OnePlus 15 opens up one of its biggest leads in the comparison. The OnePlus 15 answers with a 165 Hz display instead of 120 Hz. You notice refresh rate every time you scroll a feed or a web page, which is why the OnePlus 15 feels more fluid in everyday use. If display is your priority, the OnePlus 15 is the phone to pick.
Refresh rate
OnePlus 15: 165 Hz Galaxy S25 Ultra: 120 Hz Smoother motion is one of the most visible display upgrades, and adaptive high-refresh panels can slow down on static content to save power.
Performance
Too close to call
The OnePlus 15 and the Galaxy S25 Ultra match each other closely in this area. Both cover performance well enough that other priorities should break the tie.
Memory & Storage
Galaxy S25 Ultra leads
If you’re keeping score, the memory & storage point goes narrowly to the Galaxy S25 Ultra. In its favor, the Galaxy S25 Ultra has a bigger top storage option. Most buyers are fine with a base or middle tier, so this is a niche advantage, but a real one if you need it. On memory & storage alone, the Galaxy S25 Ultra gets the nod.
Max storage
OnePlus 15: 512 GB Galaxy S25 Ultra: 1 TB Heavy video shooters and people with large offline libraries benefit from the Galaxy S25 Ultra’s bigger maximum.
Camera
Galaxy S25 Ultra leads
The OnePlus 15 has a tough time in the camera section, where the Galaxy S25 Ultra pulls well ahead. The Galaxy S25 Ultra stands out with 5× optical zoom versus 3.5×. Higher optical zoom lets you frame distant subjects tightly without losing detail to digital cropping. The OnePlus 15 takes this one with a sharper 32 MP selfie camera. For camera, the Galaxy S25 Ultra is the one to beat.
Optical zoom
OnePlus 15: 3.5× Galaxy S25 Ultra: 5× The Galaxy S25 Ultra reaches further with real optics, which pays off for wildlife, stages and sports from the stands.
Main camera
OnePlus 15: 50 MP Galaxy S25 Ultra: 200 MP The Galaxy S25 Ultra’s higher-resolution main sensor gives you more room to crop, which helps when you can’t get closer.
Battery & Charging
OnePlus 15 leads
This is one of the OnePlus 15’s strongest areas. On battery & charging, the Galaxy S25 Ultra falls well short. On its side, the OnePlus 15 has 46% more battery capacity. Capacity isn’t everything, but when two phones are otherwise close, more milliamp-hours is the simplest endurance advantage there is. For anyone who cares most about battery & charging, the OnePlus 15 is the safer choice.
Battery capacity
OnePlus 15: 7,300 mAh Galaxy S25 Ultra: 5,000 mAh A bigger battery usually means longer days between charges, although chip efficiency and screen size also shape real endurance.
Wired charging
OnePlus 15: 120 W Galaxy S25 Ultra: 45 W Peak charging speeds depend on a compatible charger, which may not come in the box.
Software & Updates
Galaxy S25 Ultra leads
The Galaxy S25 Ultra wins the software & updates section decisively. The Galaxy S25 Ultra delivers 3 years of extra promised updates. A longer update promise keeps the phone secure and current for longer, which matters if you keep devices for several years. The takeaway: on software & updates, the Galaxy S25 Ultra is the stronger phone.
Promised OS updates
OnePlus 15: 4 years Galaxy S25 Ultra: 7 years Software support is what separates a phone that ages gracefully from one that doesn’t, making it one of the most practical lines on the spec sheet.
Full Specifications
Display
| Spec | OnePlus 15 | Galaxy S25 Ultra |
|---|---|---|
| Screen size | 6.8 in | 6.9 in |
| Panel type | LTPO AMOLED | Dynamic AMOLED 2X |
| Resolution | 2772 x 1272 | 3120 x 1440 |
| Pixel density | N/A (not specified) | 498 ppi |
| Refresh rate | 165 Hz (winner) Smoothest display in class | 120 Hz |
| Peak brightness | N/A (not specified) | 2,600 nits |
| Always-on display | Yes | Yes |
Performance
| Spec | OnePlus 15 | Galaxy S25 Ultra |
|---|---|---|
| Chipset | Snapdragon 8 Elite Gen 5 | Snapdragon 8 Elite for Galaxy |
| CPU cores | 8 | 8 |
| Process node | 3 nm | 3 nm |
| RAM | 12 GB | 12 GB |
Memory & Storage
| Spec | OnePlus 15 | Galaxy S25 Ultra |
|---|---|---|
| Base storage | 256 GB | 256 GB |
| Max storage | 512 GB | 1 TB (winner) |
| microSD slot | No | No |
Camera
| Spec | OnePlus 15 | Galaxy S25 Ultra |
|---|---|---|
| Main camera | 50 MP | 200 MP (winner) |
| Ultra-wide camera | 50 MP | 50 MP |
| Telephoto camera | 50 MP | 50 MP |
| Optical zoom | 3.5× | 5× (winner) |
| Rear cameras | 3 | 4 (winner) |
| Front camera | 32 MP (winner) | 12 MP |
| Max video | N/A (not specified) | 8K30 |
Battery & Charging
| Spec | OnePlus 15 | Galaxy S25 Ultra |
|---|---|---|
| Battery capacity | 7,300 mAh (winner) Biggest battery in class | 5,000 mAh |
| Wired charging | 120 W (winner) Fastest wired charging | 45 W |
| Wireless charging | 50 W (winner) | 15 W |
| Port | USB-C (USB 3.2) | USB-C |
Software & Updates
| Spec | OnePlus 15 | Galaxy S25 Ultra |
|---|---|---|
| OS at launch | OxygenOS 16 (Android 16) | Android 15 (One UI 7) |
| Promised OS updatesManufacturer commitment | 4 years | 7 years (winner) |
Design & Build
| Spec | OnePlus 15 | Galaxy S25 Ultra |
|---|---|---|
| Height | 6.35 in | 6.41 in |
| Width | 3.02 in | 3.06 in |
| Thickness | 0.32 in | 0.32 in |
| Weight | 7.44 oz | 7.69 oz |
| Water & dust rating | IP68/IP69 (winner) | IP68 |
| Frame | Aluminum | Titanium |
Price
| Spec | OnePlus 15 | Galaxy S25 Ultra |
|---|---|---|
| Launch price | $900 (winner) | $1,300 |
“N/A” means the manufacturer does not specify the value or we could not confirm it. Figures marked “manufacturer rating” are the maker’s own claims, not our measurements.
Price & Value
The OnePlus 15 launched at $400 less than the Galaxy S25 Ultra, a gap of 44%. Neither leads outright, so ask yourself whether the Galaxy S25 Ultra’s strengths are worth $400 more to you.
These are US launch prices, recorded November 2025; what you pay today may be higher or lower.
Which One Should You Buy?
Choose the OnePlus 15 if…
- you often spend long days away from a charger (7,300 mAh vs 5,000 mAh)
- you want smoother scrolling (165 Hz vs 120 Hz)
- you often need a quick top-up before heading out (120 W vs 45 W wired)
- you take a lot of selfies or video calls (32 MP vs 12 MP front camera)
- you’re working to a firm budget and $400 matters
Choose the Galaxy S25 Ultra if…
- you plan to keep your phone for years (7 years vs 4 years of promised updates)
- you shoot concerts, sports or wildlife from a distance (5× vs 3.5× optical zoom)
- you like to crop into your photos (200 MP vs 50 MP main camera)
- you like switching between focal lengths (4 vs 3 cameras)
Also Compared
Frequently Asked Questions
Should I buy the OnePlus 15 or the Galaxy S25 Ultra?
The Galaxy S25 Ultra has its strengths, but the OnePlus 15 saves $400, which makes it the value pick.
Which has better battery life, the OnePlus 15 or the Galaxy S25 Ultra?
On paper, the OnePlus 15 has the edge: 7,300 mAh of battery capacity against 5,000 mAh for the Galaxy S25 Ultra. Real-world results also depend on how you use it.
Which is larger, the OnePlus 15 or the Galaxy S25 Ultra?
Size is essentially a tie. The official dimensions of the OnePlus 15 and the Galaxy S25 Ultra differ only marginally.
Does the OnePlus 15 have a stronger camera setup than the Galaxy S25 Ultra?
On paper, the Galaxy S25 Ultra has the stronger camera setup, with 5× optical zoom versus 3.5× and a higher-resolution 200 MP main camera.
Is the OnePlus 15’s display better than the Galaxy S25 Ultra’s?
The OnePlus 15 has the stronger display on paper, with a 165 Hz display instead of 120 Hz.
Is the OnePlus 15 cheaper than the Galaxy S25 Ultra?
The Galaxy S25 Ultra launched at $400 more than the OnePlus 15, based on prices as of November 2025.
Executive Summary
On paper, the OnePlus 15 and the Galaxy S25 Ultra chase the same buyer. In the details, OnePlus and Samsung made different calls. I keep coming back to one thing: the OnePlus 15 gets 46% more battery capacity. There’s a bonus as well: the OnePlus 15 has a 165 Hz display instead of 120 Hz. The Galaxy S25 Ultra does have a strong card to play: 3 years of extra promised updates.
For display, the OnePlus 15 fits better. For memory & storage, the Galaxy S25 Ultra is the better match.
My pick: the OnePlus 15, because value matters and $400 is real money.
Personal opinion based on the data above. Your priorities may differ.