OnePlus Watch 3 Review – Incredible battery life makes this the best WearOS watch for 2025

The OnePlus Watch 3 marks the third iteration of OnePlus’s wearable technology, and it’s quite clear that the company has been listening to feedback from previous generations.

While the smartwatch market is highly competitive, there are not many viable WearOS watches. Samsung dominates the WearOS market, then Google has the Pixel watch, and  Mobvoi is a popular, affordable option.

With its third WearOS watch, OnePlus appears to have done what Samsung and Google have consistently failed to do: produce a watch with great battery life. For this reason alone, I think the OnePlus Watch 3 is by far the best WearOS watch on the market.

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Specification

Features

Dual-Engine Architecture, Long-Lasting Battery Life

The OnePlus Watch 3 delivers exceptional battery life alongside strong performance. Users can expect up to 3 days in heavy-use mode, 5 days in smart mode, and an impressive 16 days in power-saving mode.

The watch achieves this through several technical improvements. The battery capacity has been increased to 631mAh and incorporates OnePlus Silicon NanoStack Battery technology—the same used in the OnePlus 13 smartphone—which provides higher energy density while maintaining a slim profile. The new BES2800 chipset, built on 6nm FinFET technology, improves both CPU and NPU processing capabilities compared to previous models while reducing power consumption.

The OnePlus-developed Dual-Engine Architecture employs two distinct chipsets—the Snapdragon W5 for performance-intensive tasks and the BES2800 MCU for efficiency. The BES2800 handles background processes under RTOS, while the Snapdragon W5 manages more demanding operations like Google apps. This hardware-software combination allows the watch to balance performance and battery life across different usage scenarios.

Health Tracking Made Simple and Smart

The OnePlus Watch 3 offers comprehensive health monitoring capabilities. The standout 60S Health Check-In feature provides a quick health assessment by pressing the All-in-One Scan button, delivering a detailed report within 60 seconds. This report covers seven key health metrics: heart rate, electrocardiograph (ECG), blood oxygen levels, mental wellness, wrist temperature, sleep quality, and vascular age.

Heart health monitoring is a priority, with an enhanced photoplethysmography (PPG) sensor featuring an eight-channel heart rate sensor. Combined with the curved strap design that improves fit, the watch provides accurate heart rate detection. The single-lead ECG function can identify atrial fibrillation, sinus rhythm, high and low heart rates, and significant heart rate fluctuations.

The watch also monitors vascular health, allowing users to compare their vascular condition against age-based benchmarks. Using ECG and PPG technology, it assesses vascular elasticity and helps identify risks related to arterial stiffness.

The 360 Mind and Body feature provides insights into physical and mental wellbeing through multi-dimensional data analysis. By tracking metrics like HRV (Heart Rate Variability), resting heart rate, and activity intensity, the watch uses health algorithms to assess emotional and stress levels. The interface includes a dynamic emoji reflecting the user’s current state, and offers breathing exercises based on detected stress conditions.

Enhanced Fitness Monitoring

The OnePlus Watch 3 elevates sports tracking with advanced sensors and improved algorithms. Its dual-frequency GPS provides faster and more accurate outdoor activity tracking, precisely measuring distance and route trajectories. The watch performs particularly well in specific environments such as running tracks.

With support for over 100 sports modes—including running, walking, cycling, swimming, hiking, skiing, various racquet sports, team sports, and yoga—the watch caters to diverse fitness activities. It features 11 professional modes for detailed data tracking, such as the upgraded running mode that monitors both performance and posture across different running scenarios.

The watch also analyses fat and carbohydrate consumption within different heart rate zones, offering insights into fat-burning efficiency, workout intensity, and exercise effectiveness. This data helps users manage exercise intensity, stay within optimal training ranges, and adjust workouts for safe, effective results—particularly valuable for weight management goals.

Seamless Ecosystem Integration with Wear OS 5

The OnePlus Watch 3 runs on the latest Wear OS, bringing updates to essential Google applications. Users can switch their watch to a new phone without needing to reset the device. Gmail on Wear OS 5 now supports email synchronisation and reply functions, streamlining email management. Google Wallet has been expanded to support boarding passes, making travel more convenient.

Effortless Connectivity within the OnePlus Ecosystem

When paired with OnePlus smartphones, the Watch 3 serves as a remote control for various functions. Users can control video playback on platforms like TikTok and YouTube Shorts, as well as operate the phone’s camera directly from the watch.

Premium Design and Military-Grade Durability

The OnePlus Watch 3 features a refined round design crafted from durable stainless steel. Its Titanium PVD (Physical Vapor Deposition) bezel provides both an elegant shine and excellent corrosion resistance. The 1.5-inch LTPO flexible display uses 2D Sapphire Crystal for superior durability and brightness.

Built to MIL-STD-810H military standards, the watch withstands challenging environmental conditions. With IP68 and 5ATM water resistance ratings, it performs reliably in diverse settings—from beaches to deserts to swimming pools.

The watch includes a redesigned rotating crown that offers smooth, intuitive navigation through the various watch functions, creating a seamless user experience.

Design / Unboxing

The OnePlus Watch 3 maintains a similar shape to its predecessor but introduces some notable refinements. The most striking addition is the titanium bezel surrounding the watch face, which gives it a more premium appearance. This is complemented by a stainless steel case, creating a watch that genuinely looks like a traditional timepiece rather than a piece of technology strapped to your wrist.

At 47mm, this is undeniably a large watch. The dimensions come in at 46.6mm × 47.6mm × 11.75mm (excluding the sensor area), making it quite substantial on smaller wrists. It’s also relatively heavy at 81g with the strap attached (49.7g for the watch body alone). I personally don’t mind larger watches, and it is a similar size to my Garmin Epix Gen 2, this might be a dealbreaker for those with smaller wrists or who prefer more discreet wearables. The Pixel watch regularly gets criticised for being too small, so unless brands produce multiple-sized watches like Apple, Samsung and Garmin, there will always be criticism of the dimensions.

The watch is available in two colour options: Emerald Titanium (silver) and Obsidian Titanium (black). I’ve been testing the Emerald Titanium version, which features a silver case with matching titanium bezel. The finish is excellent, with the titanium bezel adding a touch of class that was missing from previous generations. Based on the pictures, I think this colour option is more attractive than the Obsidian Black.

One of the most significant improvements is the rotating crown, which is now fully functional. This makes navigating through menus and notifications much more intuitive than relying solely on the touchscreen. There’s also a secondary button that can be customised to launch specific apps or features.

As a fitness enthusiast, I would prefer more physical buttons so I don’t have to try and use the touchscreen when sweaty/wet.

The watch comes with a standard 22mm rubber strap that’s perfectly comfortable for everyday wear. The quick-release mechanism makes it easy to swap out for different bands if you want to change up the look. I found the included strap comfortable enough for both day wear and sleep tracking.

In terms of durability, OnePlus has gone all out. The watch features sapphire crystal glass protecting the display, which should resist scratches effectively. It’s also built to MIL-STD-810H military standards, meaning it can withstand a range of harsh conditions including extreme temperatures, humidity, salt spray, vibration, and impact. With IP68 water and dust resistance and 5ATM water resistance rating, you can wear it while swimming without concern.

Display

The OnePlus Watch 3 sports a slightly larger 1.5-inch AMOLED display compared to its predecessor’s 1.43-inch screen. The resolution remains at 466 × 466 pixels, which provides crisp text and vibrant colours.

What’s particularly impressive is the brightness capability. The watch can reach up to 2,200 nits in certain conditions (particularly during workouts in bright sunlight), which is a substantial improvement over the previous generation’s 600 nits. This makes the display easily readable even in direct sunlight, which has been a common complaint with many smartwatches.

The display uses LTPO (Low-Temperature Polycrystalline Oxide) technology, allowing it to dynamically adjust its refresh rate from 1Hz to 60Hz depending on what’s being displayed. This helps conserve battery life when showing static content like the always-on display while providing smooth animations when actively using the watch.

The auto-brightness feature works well, quickly adjusting to changing lighting conditions. I found that even when moving from indoors to bright sunlight, the display remained perfectly legible without any manual adjustments needed.

The always-on display option is available and works as expected, showing a simplified version of your chosen watch face when the watch is idle. It’s worth noting that enabling this feature will impact battery life, though not as dramatically as on some other WearOS watches thanks to the efficient LTPO display. Throughout my testing, I left the display in the default raise to wake mode.

Touch responsiveness is excellent, with no noticeable lag when swiping through menus or tapping on apps. Combined with the rotating crown, navigating the watch’s interface feels intuitive and smooth.

Set-Up

Setting up the OnePlus Watch 3 is straightforward. You’ll need to download the OHealth app from the Google Play Store, pair your watch, and follow the on-screen instructions. The entire process takes just a few minutes and is relatively painless.

The watch runs WearOS 5, Google’s latest wearable operating system, alongside a Real-Time Operating System (RTOS) that powers the power-saving mode. This dual-OS approach is one of the key factors behind the watch’s impressive battery life.

In standard WearOS mode, you get access to the full range of Google services including Google Wallet for contactless payments, Google Maps for navigation, and the Google Play Store for downloading additional apps. The interface is clean and intuitive, with a swipe down revealing quick settings, a swipe up showing notifications, and swipes left or right cycling through your tiles (customisable widgets).

The OHealth app serves as the companion app for the watch, allowing you to customise watch faces, manage notifications, and view your health and fitness data. The app is divided into four main sections:

• Home: Shows various health stats measured by your watch
• Health: Displays health insights and your health journey
• Fitness: Shows fitness stats and workout records
• Devices: Allows you to manage your watch, including watch faces, tiles, and other settings

The app works well enough, though it doesn’t quite have the polish of Samsung’s or Apple’s companion apps. Some of the health data presentations could be clearer, and there are occasional translation quirks that betray the app’s non-native English origins.

It is worth noting that I did have some issues setting up the watch at first, but I am 99% sure this was due to the Xiaomi 15. There is something funny going on with the new Bluetooth 6.0. Pairing it with my Pixel 9 Pro XL worked flawlessly and I was then able to transfer it over to my Xiaomi 15.

Performance

The OnePlus Watch 3 employs a dual-chipset architecture, using the Snapdragon W5 for performance-intensive tasks and the BES2800 for efficiency. This combination, along with 2GB of RAM, delivers smooth performance across the board.

Navigating through the interface is fluid, with no noticeable lag when swiping between screens or opening apps. The watch responds promptly to inputs, whether from the touchscreen or the rotating crown. Even more demanding apps like Google Maps run without issues.

The dual-architecture approach also allows the watch to intelligently manage power consumption. For less intensive tasks like checking the time or notifications, the watch can use the more efficient BES2800 chip, saving battery life without compromising the user experience.

During my testing, I didn’t encounter any performance issues or crashes. Apps opened quickly, and the watch remained responsive even after several days of continuous use without restarting.

The only minor gripe maybe when the watch goes into hibernation mode at night. In the morning, I have to disable hibernation mode, and it takes quite a while for the full smart mode to be enabled. I think my unusual sleep pattern contributes to this problem, the watch gets a bit confused about me getting up at 3am.

Smart Features

As a WearOS device, the OnePlus Watch 3 offers a comprehensive set of smart features. Notification handling is good, with clear, readable alerts that you can respond to directly from the watch using voice input, the on-screen keyboard, or pre-set responses. The keyboard is surprisingly usable given the screen size, though voice input remains the most efficient way to reply to messages.

Google Assistant is available by long-pressing the crown button, and it works well for setting timers, checking the weather, or controlling smart home devices. The microphone does a decent job of picking up voice commands, even in moderately noisy environments.

Contactless payments work flawlessly with Google Wallet, making it convenient to pay for items without reaching for your phone or wallet. The watch also supports Bluetooth calling, allowing you to take calls directly on your wrist. The speaker isn’t particularly loud, but it’s adequate for quick conversations in relatively quiet settings. I do find this a bit of a gimmick, or at least only useful for very limited situations.

The app selection through the Google Play Store is robust, with popular options like Spotify, Strava, and various messaging apps available. The 32GB of storage provides plenty of space for apps and offline music if you want to leave your phone behind during workouts.

One of the more useful features is the ability to transfer your watch to a new phone without needing to reset it, which is a welcome addition in WearOS 5. This makes upgrading your phone much less of a hassle if you’re a smartwatch user.

Health Tracking

The OnePlus Watch 3 comes equipped with an good array of health sensors, including an optical heart rate sensor, blood oxygen sensor, ECG sensor (though availability varies by region), and a wrist temperature sensor.

One interesting health feature is the 60-second health check-in, which provides a comprehensive overview of your health by measuring multiple metrics simultaneously. This includes heart rate, ECG (where available), blood oxygen, mental wellness, wrist temperature, sleep quality, and vascular age. It’s a convenient way to get a snapshot of your overall health status.

Sleep tracking works well, accurately detecting when you fall asleep and wake up. The watch provides a breakdown of sleep stages (light, deep, and REM) and gives you an overall sleep score. It can also detect naps during the day, which is a nice touch. The watch automatically enters a sleep mode when it detects you’re sleeping, which helps conserve battery life.

Heart rate monitoring seems generally accurate during rest and light activity. During more vigorous activity, I have found the performance to be poor, but this is not a unique problem with the OnePlus. I have thin, bony and hairy wrists, which is sub-optimal for wrist-based heart rate monitoring.

In the screenshots above, you can see that the watch was completely off with my heart rate. It locked on to 180 bpm for the majority of my run. My Garmin seems to have the opposite problem at the moment, it seems to stick at a much lower heart rate.

The watch offers over 100 workout modes, including running, cycling, swimming, and various other activities. For outdoor activities, the dual-frequency GPS provides accurate tracking of your route and distance. During my testing, GPS accuracy was good, locking on quickly and maintaining a consistent track throughout workouts.

The running mode provides detailed metrics, including pace, distance, cadence, and even more advanced data like ground contact time and balance. I was particularly impressed to see that OnePlus also have running power included. This is an advanced running metric that is only available on the more recent and expensive Garmin models.

For swimmers, the watch tracks laps, distance, stroke count, and SWOLF score (a measure of swimming efficiency).

One interesting feature is the analysis of fat and carbohydrate consumption within different heart rate zones, which can help you understand the effectiveness of your workouts for weight management goals.

The watch also monitors your stress levels throughout the day and offers breathing exercises to help manage stress when it detects elevated levels. The new 360 Mind and Body feature aims to provide insights into your physical and mental well-being through multi-dimensional data analysis, though this feature wasn’t fully available during my testing period.

Overall, while the fitness features don’t compete with Garmin, they are superb for a WearOS watch, and this does almost everything I want from a fitness watch.

ECG and Regional Availability

One feature that deserves special mention is the ECG (electrocardiogram) functionality. The OnePlus Watch 3 includes the necessary hardware for ECG readings, which can help detect irregular heart rhythms like atrial fibrillation.

However, due to regulatory requirements, this feature isn’t available in all regions at launch. In the UK, OnePlus states that ECG functionality will be enabled in Q3 2025 after receiving the necessary medical certifications.

Battery Life

By far, the standout feature of this watch is the incredible battery life of a WearOS device.

Admittedly, I don’t review many WearOS watches, and I know options such as the £500 Samsung Galaxy Watch Ultra have larger batteries. However, the Ultra still only claims up to 80 hours, which works out for 3 days and 8 hours.

The OnePlus Watch 3 claims up to 5 days in smart mode and 3 days with heavy use.

Based on my usage, the 5-day claims are accurate.

In the past week, I charged it on a Monday morning and only charged again on Sunday as I was going on a walk, and the watch was at 15% and in battery-saving mode.

I’d say my usage is reasonably light. I predominantly use the watch exactly how I use my Garmin, which is for fitness tracking and general notifications.

One feature that seems to extend the battery life significantly is when you go to sleep the watch enters hibernation mode. In this mode, most of the watch features are disabled, it just keeps the sleep-tracking features enabled.

Price and Alternative Options

The OnePlus Watch 3 has an RRP of £319 but at the time of writing it was discounted to £269.

There is also a trade-in offer with a guaranteed £30 discount and various 10% discounts for various groups of people including seniors, students, and different job industries.

Additionally, you can get a free gift, with the OnePlus Nord Buds 3 Pro being the best option or a choice of an additional strap.

The Samsung Galaxy Watch is the best alternative, and this has multiple variants:

• Galaxy Watch7 Bluetooth (40mm) – £214
• Galaxy Watch7 Bluetooth (44mm) – £244
• Galaxy Watch Ultra LTE (47mm) – £500

The Google Pixel Watch 3 starts at £349

Xiaomi has the Watch 2 Pro, which has an RRP of £240 but is available for £160, and it is rumoured the new Xiaomi Watch 3 Pro may launch soon.

Overall

The OnePlus Watch 3 is the WearOS watch I have been waiting years for. Thanks to its outstanding battery life, it is the first time I’d consider moving from Garmin.

For Android users looking for a smartwatch that doesn’t need daily charging, the OnePlus Watch 3 is an excellent choice. It handles the basics of notification management and fitness tracking well while offering the full WearOS experience, including Google services and third-party apps.

At its price point, the OnePlus Watch 3 offers excellent value, particularly when compared to premium offerings from Samsung and Google that cost more but offer less battery life. If you’re in the market for a WearOS smartwatch and don’t mind the larger size, the OnePlus Watch 3 should be high on your list of options to consider.

James Smythe( Editor-in-chief )

I am James, a UK-based tech enthusiast and the Editor and Owner of Mighty Gadget, which I’ve proudly run since 2007. Passionate about all things technology, my expertise spans from computers and networking to mobile, wearables, and smart home devices.

As a fitness fanatic who loves running and cycling, I also have a keen interest in fitness-related technology, and I take every opportunity to cover this niche on my blog. My diverse interests allow me to bring a unique perspective to tech blogging, merging lifestyle, fitness, and the latest tech trends.

In my academic pursuits, I earned a BSc in Information Systems Design from UCLAN, before advancing my learning with a Master’s Degree in Computing. This advanced study also included Cisco CCNA accreditation, further demonstrating my commitment to understanding and staying ahead of the technology curve.

I’m proud to share that Vuelio has consistently ranked Mighty Gadget as one of the top technology blogs in the UK. With my dedication to technology and drive to share my insights, I aim to continue providing my readers with engaging and informative content.