OnePlus 15 review: a practical flagship with insane battery life

After living with the OnePlus 15 for a solid two weeks, I’m convinced this is the most grown-up phone the company has ever made. Not the flashiest, not the weirdest, but the one where OnePlus finally stopped chasing gimmicks and started obsessing over the things that actually define a great daily driver: battery life, performance, reliability and a camera that you don’t have to fight with.

In a market dominated by the iPhone, Galaxy and Pixel, the OnePlus 15 doesn’t try to shout over them. Instead, it quietly shows up with ridiculous stamina, gaming-class performance and a price that makes the usual flagships look slightly awkward.

That shift in priorities is what impressed me the most. On paper, some decisions look like steps backward: the iconic Alert Slider is gone, the design language has been toned down, and the curved display that used to scream “premium” has been flattened out. Even the camera hardware looks less ambitious at first glance. But once you stop judging the phone by its spec sheet or its press renders and actually live with it, the logic behind the OnePlus 15 becomes very clear: this is a practical flagship built for people who use their phone hard, not for those who just want something ornate to put on the table.

Design: from bold and loud to flat and functional

Let’s get this out of the way: from across the room, the OnePlus 15 could easily be mistaken for yet another iPhone-style slab. The rounded corners, the flat frame, the centered camera module – nothing about it screams “Only OnePlus would do this.” The Alert Slider, one of the brand’s signature touches, has disappeared, and the once-dramatic curves of the display are now history.

And yet, the more I used it, the more I appreciated this seemingly generic design. The flat sides give you a much better grip and make it easier to hold the phone securely with one hand. If it slips out of your pocket or off the couch, those flat edges give it a fighting chance. The flat display makes installing a screen protector a five-minute job instead of a frustrating gamble. The updated IP rating means you’re less worried about rain, splashes or dusty environments. It’s the opposite of glamorous, but it feels like a phone that’s designed to survive actual life, not just photo shoots.

The front is dominated by a bright OLED panel that gets close to 3,500 nits in peak brightness. Outdoors, it punches through strong sunlight, but reflections still creep in more than I’d like. OnePlus clearly nailed the brute force brightness, but the anti-reflective coating could be better; in harsh light you still find yourself tilting the phone to chase away glare.

Display and refresh rate: hidden gaming credentials

The display runs at 120Hz in everyday use, which is what you’d expect from a flagship in 2025. Animations are fluid, scrolling is buttery smooth and the whole interface feels responsive in a way that’s hard to give up once you’ve experienced it. But buried underneath that, the OnePlus 15 hides a little extra: support for up to 165Hz in select titles.

This ultra-high refresh rate doesn’t kick in everywhere, and in regular apps the phone behaves like a standard 120Hz device. But in a handful of competitive games that support it, that 165Hz mode gives you an extra edge – quicker visual feedback, slightly smoother tracking and a sense that the phone is ready to keep up with the fastest reflexes. OnePlus has essentially packed a mini gaming phone into a mainstream flagship shell, without turning it into a neon-lit toy.

Camera: lower profile on paper, better tuned in reality

The OnePlus 15 makes a risky first impression on camera nerds. The main sensor is slightly smaller than before, and the Hasselblad branding has vanished from the back. On a spec sheet, that reads like a downgrade; in a world obsessed with Xiaomi Ultras and Galaxy Ultras, it almost looks like surrender.

Then you start shooting with it, and the story changes. Daytime photos look more natural than on previous OnePlus phones, with warmer tones and a more realistic way of handling skin. The classic over-sharpened, plastic look that used to haunt OnePlus cameras has been dialed down significantly. The jump to 26MP default shots brings noticeably more detail without blowing up noise, and it gives you a little extra freedom to crop without everything falling apart. It’s the kind of quiet improvement that matters more than slapping another logo next to the lenses.

Night performance is where the change becomes even more obvious. Instead of turning every scene into a hyper-saturated, HDR-heavy fireball, the OnePlus 15 finally behaves like a mature camera. Highlights are controlled, shadows are lifted just enough to be usable, and colors stay closer to what your eyes remember. You don’t get the cinematic processing of an iPhone or the extreme dynamic range of a Galaxy S25 Ultra, but you also don’t get the overcooked chaos that older OnePlus phones sometimes produced.

It’s not perfect, of course. The ultra-wide camera doesn’t match the color temperature of the main sensor, often producing slightly cooler, bluer shots. Jumping between lenses can still result in small but noticeable shifts in tone and contrast. And some software features feel oddly absent for a 2025 flagship – for example, the ability to retroactively add portrait blur to a regular image is still missing. Video performance is solid and reliable rather than mind-blowing, which is fine for most users but will leave serious creators leaning toward Apple or Samsung.

Performance: Snapdragon 8 Elite Gen 5 unleashed

If the camera is a big step forward in subtle ways, performance is a full-on sprint. The Snapdragon 8 Elite Gen 5 inside the OnePlus 15 absolutely tears through everything thrown at it. Apps launch instantly, multitasking is effortless, and heavy games run at sustained high frame rates without the phone turning into a hand warmer.

In intense stress tests like 3DMark’s Wildlife Extreme loop, the phone maintains around 99% stability, which is wild. There’s no dramatic thermal throttling curve, no sudden drops in performance after a few minutes of pushing it. This is one of the rare devices where benchmarks and real-world performance line up almost perfectly. Long gaming sessions feel smooth not just in the first 10 minutes, but an hour later too.

The base configuration gives you 12GB of LPDDR5X RAM and 256GB of storage, which is already generous compared to some competitors that still charge you extra to escape 8GB/128GB combos. But the sweet spot is the 16GB/512GB model, which OnePlus sells for about $100 more and equips with even faster Ultra+ RAM. Combined with OnePlus’ long-standing obsession with animation smoothness and UI snappiness, the result is a phone that feels fast everywhere, not just in benchmarks.

Battery life: a 7,300 mAh cheat code

This is where the OnePlus 15 stops competing with other flagships and starts bullying them. While the Galaxy S25 Ultra ships with a respectable 5,000 mAh battery, the OnePlus 15 rolls in with a massive 7,300 mAh cell. On paper, that sounds unfair. In practice, it kind of is.

In mixed use, the phone comfortably behaves like a two-day device. Light users can stretch it beyond 30 hours of screen-on time over a couple of days. In more structured testing, the OnePlus 15 pulls off more than 12 hours of continuous YouTube streaming and close to 14 hours of nonstop gaming. These aren’t just big numbers; they change how you relate to the phone. Instead of constantly glancing at the battery percentage or hunting for a charger during a long day out, you simply stop worrying.

Charging, predictably for OnePlus, is excellent. A full charge from near-empty to 100% takes around 45 minutes with the included fast charger. It’s the classic OnePlus quality-of-life advantage that once you get used to, feels very hard to give up. Wireless charging works fine too, though the lack of Qi2 magnetic wireless charging feels like a missed opportunity in a world where magnetic accessories are quickly becoming the norm.

Software: fast, familiar… maybe a little too familiar

The software experience is where the OnePlus 15’s maturity is both an advantage and a limitation. On the positive side, the interface is fast, fluid and visually consistent. Animations are tuned to feel snappy rather than showy, and everything from opening the camera to switching between heavy apps feels immediate.

But it’s hard to ignore how much the UI leans on iOS-style visual ideas. From icon shapes to certain layout choices, parts of OxygenOS on the OnePlus 15 feel more like an imitation than an evolution of OnePlus’ earlier identity. Some users will love the familiarity; others will wish the phone had a stronger personality of its own.

Not all third-party apps are perfectly optimized either. You occasionally run into screens with odd empty spaces, font sizes that feel slightly off or elements that don’t scale gracefully. None of this breaks the experience, but it does remind you that software polish is one area where Samsung, Google and Apple still lead.

Another drawback is long-term support. The OnePlus 15 offers four years of software updates, which is decent but clearly behind the five-plus-year commitments from Samsung and Google’s latest flagships. If you tend to keep your phone for a very long time, that’s worth factoring in.

Audio is similarly mixed. The stereo speakers get loud, but at higher volumes the sound becomes muddy and loses some clarity. For podcasts and casual video watching, they’re fine; for music, you’ll probably want good headphones.

Competition, camera wars and the Xiaomi factor

In the broader flagship landscape, the OnePlus 15 slots into an interesting space. If you want the absolute best all-around camera system, the latest iPhones and Samsung’s Galaxy S25 Ultra still have the edge. They offer more consistent image processing across all focal lengths, stronger video tools and longer software support.

Then there are the camera-obsessed Android rivals from China, like the upcoming Xiaomi 17 Ultra that many enthusiasts expect to be a monster in mobile photography. If camera experimentation, giant sensors and aggressive zoom systems are your top priority, those ultra-flagships are likely to keep grabbing headlines and topping camera rankings.

The OnePlus 15 doesn’t try to win that arms race. Instead, it aims to be the phone that feels almost unfairly easy to live with: “very good” cameras, “insane” battery life, desktop-class performance and a price tag that undercuts many of its most hyped rivals. It’s a more grounded proposition, targeted at people who want something that just handles everything without drama.

So, should you buy the OnePlus 15 in 2025 or early 2026?

If your dream phone is a pocket camera with phone features attached, the OnePlus 15 probably won’t replace an iPhone Pro, a Galaxy Ultra or whatever Xiaomi cooks up next in the “Ultra” line. Those devices still do more with zoom, video tools and long-term software support.

But if you’re okay with a camera that is simply reliable and very good rather than absolute best in class, the OnePlus 15 suddenly becomes a very compelling choice. You get absurd battery life, genuinely top-tier performance, fast charging that resets your expectations, and a design that may be visually boring but is wonderfully practical in everyday use.

The shortcomings are real – slightly derivative software, only four years of updates, imperfect anti-reflective coating, no Qi2 magnetic charging and speakers that don’t match the best in the business. None of these feel like deal-breakers though. They feel like reminders that this is a focused flagship, not an attempt to out-spec every rival in every category.

In a world where many premium phones are trying to be everything at once, the OnePlus 15 wins by being brilliant at the fundamentals. If battery life, speed and no-nonsense practicality are top of your list, this might be the sleeper hit of 2025 and the phone you’ll still be happily using well into 2026.