When OnePlus first entered the smartwatch arena, the results were promising but uneven. The original OnePlus Watch looked the part but stumbled with its clunky software and limited app ecosystem. Fast forward to 2025, and the company seems determined to rewrite that story with the OnePlus Watch 3 43mm, priced at £229 at the time of writing, as it has a flash sale, but the normal price is £269, a Wear OS device that combines premium materials, thoughtful design, and deep Android integration.

But the version that’s perhaps the most intriguing is the 43 mm model. While the larger 46 mm Watch 3 gets the flagship spotlight, this smaller edition aims for comfort and subtlety without cutting too many corners. It’s a watch designed for smaller wrists, lighter wear, and everyday use, and after several weeks with it, I can confidently say it’s one of the most refined smartwatches OnePlus has produced.

Design & Build Quality: Small Frame, Big Impression

The OnePlus Watch 3 (43 mm) immediately impresses with its elegant proportions. OnePlus has streamlined the design into a perfectly symmetrical circle — no bulky edges, no offset buttons, and none of the design awkwardness that plagued earlier models.

The case itself is forged from stainless steel with a titanium alloy bezel, topped by sapphire crystal glass. It feels every bit as premium as smartwatches costing twice as much. The build has passed MIL-STD-810H durability testing and carries 5ATM + IP68 resistance, meaning it’s safe for rain, showers, and casual swims (though OnePlus cautions against saunas or diving).

At 43 mm across and weighing roughly 21 grams less than the 46 mm version, it’s remarkably comfortable, particularly for those who find most smartwatches too bulky. The reduced footprint makes it easier to wear overnight for sleep tracking or during workouts where movement freedom matters.

The rotating digital crown on the right side is tactile, responsive, and satisfying to use. It adds a classic watch feel while providing precise scrolling through menus.

The button just below it doubles as a shortcut for apps or workouts. Overall, OnePlus nails the premium fit and finish here — this is a watch that looks and feels luxurious, yet still understated.

Display: Bright, Sharp, and Efficient

The Watch 3 (43 mm) features a 1.32-inch LTPO AMOLED display, and it’s gorgeous. The LTPO panel allows the refresh rate to scale dynamically — meaning the screen ramps up for smooth animations but drops down to preserve battery life when static.

It’s bright enough to stay perfectly legible in direct sunlight, with excellent contrast and vivid colours that make watch faces pop. The bezels are slim, creating a nearly edge-to-edge illusion despite the smaller size. In short, this is one of the best displays you can get on a compact smartwatch right now.

The Always-On Display (AOD) mode works beautifully, too. Even under harsh daylight, the watch face remains crisp, and gestures wake the screen instantly. The adaptive brightness tuning feels smarter than before — rarely too dim indoors or glaringly bright at night.

Software Experience: Wear OS Meets Oxygen Polish

Under the hood, the OnePlus Watch 3 runs Wear OS 4 with OnePlus’s own optimisations. It’s powered by the Snapdragon W5 Gen 1 chipset, paired with a low-power co-processor that handles background health tracking and notifications efficiently.

The result is one of the smoothest Wear OS experiences to date. Swiping between tiles feels fluid, app loading times are near-instant, and the rotating crown scrolls through menus with minimal lag. Notifications sync seamlessly with your phone (particularly if you’re using a OnePlus or Oppo device), and Google’s full app ecosystem is here — including Maps, Wallet, Assistant, and Spotify.

OnePlus adds its own flair through the OHealth app, which aggregates your fitness, sleep, and wellness data into a clean, easy-to-read dashboard. It’s not as data-dense as Garmin Connect or Fitbit’s platform, but it’s fast and well-organized.

Watch face customisation is excellent, with a growing catalogue of downloadable designs and the option to tweak complications and colours to match your style.

Health & Fitness: Focused on the Essentials

The 43 mm model retains all the core health tracking features from its larger sibling, minus a few advanced sensors. You’ll still get:

• Continuous heart rate monitoring

• Blood oxygen (SpO₂) tracking

• Sleep analysis (with stage breakdown and snoring detection)

• Stress tracking via HRV

• Step counting, calories, activity goals, and more

What’s missing are the vascular health and skin temperature sensors — features that the 46 mm version includes for more advanced metrics like peripheral blood flow analysis and OnePlus’s 60-second Health Check. If you’re a quantified-self enthusiast who thrives on every datapoint, you might miss these. But for 95% of users, the essentials here are more than enough.

Fitness Tracking & GPS Accuracy

Workout tracking is comprehensive, with 100+ sports modes ranging from running and cycling to yoga and rowing. The dual-frequency L1 + L5 GPS delivers excellent accuracy — routes map tightly to reality even in challenging urban environments or wooded areas.

Heart-rate readings during exercise are consistent and aligned closely with chest-strap data in testing. There’s automatic workout detection for popular activities like walking and running, and the watch gives you live feedback (pace, cadence, splits, heart-rate zone) during sessions.

For runners and gym-goers alike, it’s a reliable fitness partner — not quite on the level of Garmin or Polar in terms of analytics depth, but easily competitive with Samsung and Google’s offerings.

Battery Life: Compact but Capable

Battery life is where many Wear OS watches stumble, but OnePlus has done well to balance performance and endurance here.

The 43 mm version houses a smaller battery (around 354 mAh), so you don’t get the marathon longevity of the 46 mm’s 5-day claims. Still, in daily use, I averaged two full days of battery life with Always-On Display, notifications, and two short workouts per day. With AOD disabled, that stretched close to three days.

When it’s time to recharge, OnePlus’s Super VOOC fast charging shines. A quick 10-minute top-up delivers nearly a day’s use, while a full charge takes about 45 minutes. And for emergencies, a Power Saver Mode kicks in, providing a stripped-down interface that dramatically extends the watch’s life — ideal when travelling or off-grid.

In short, while you’ll still need to charge it more often than a fitness band or hybrid watch, the OnePlus Watch 3 (43 mm) comfortably outpaces most compact Wear OS rivals in battery life.

Connectivity & Smart Features

The Watch 3 (43 mm) offers Bluetooth 5.3, Wi-Fi, NFC for Google Pay, and built-in GPS. 

Pairing with Android phones is smooth — especially within the OnePlus ecosystem, where it feels truly integrated. You can take calls directly from the wrist (the microphone and speaker quality are surprisingly good), respond to messages, control music playback, and use your watch as a remote camera shutter or presentation controller.

Voice control through Google Assistant works reliably, and the vibration motor is refined — subtle yet sharp enough to catch your attention without being jarring.

OnePlus has promised three years of software updates for the Watch 3 line. It’s a solid commitment, though slightly behind Samsung’s four-year promise for Galaxy Watches. Still, OnePlus’s update cadence has improved significantly since the original model, and Wear OS’s stability is miles better now.

Performance & Everyday Use

Thanks to its efficient dual-chip setup, performance is smooth and predictable. The watch wakes instantly, scrolls without hiccups, and handles multitasking gracefully — whether that’s navigating a route in Google Maps while streaming Spotify or managing notifications during a run.

OnePlus’s “Dual-Engine Architecture” splits tasks intelligently: the main chip handles demanding apps, while a co-processor takes over background tracking and AOD duties. This not only boosts endurance but keeps the watch cool to the touch, even during workouts.

The haptics are precise, the animations are fluid, and everything feels cohesive — like a finished product rather than an experiment. It’s the first OnePlus smartwatch that truly feels complete.

If you prefer a lighter, more discreet smartwatch and don’t need the advanced health tracking, the 43 mm model is the better buy. But if you want maximum endurance and sensor coverage, the 46 mm earns its premium.

Pros & Cons

✅ Pros

• Premium build with titanium, sapphire, and stainless steel

• Compact, comfortable, and beautifully proportioned

• Bright LTPO AMOLED display with AOD

• Smooth, responsive Wear OS experience

• Excellent GPS and workout tracking

• Fast charging and decent battery life

• Great everyday usability and polish

⚠️ Cons

• Lacks vascular and temperature sensors

• Slightly shorter battery life than the larger model

• The three-year update policy could be longer

• Android-only compatibility

Verdict: A Compact Powerhouse Worth Wearing

The OnePlus Watch 3 (43 mm) is a standout example of how far OnePlus has come in wearable design. It’s elegant, capable, and refreshingly compact — without feeling compromised. The smaller size brings real comfort advantages, while performance and display quality remain top-tier.

You won’t find every health sensor under the sun here. Still, you do get a balanced, thoughtfully engineered smartwatch that delivers where it matters: design, display, responsiveness, and day-to-day practicality.

If you’re an Android user who values subtlety, style, and a smooth Wear OS experience, the OnePlus Watch 3 (43 mm) is one of the best compact smartwatches you can buy right now.

TNC Score

4.1/5.0