Best Fitness Trackers & Smartwatches UK 2025

The Best Fitness Trackers and Smartwatches in the UK for 2025

The wearable technology market has exploded in recent years, and choosing between a fitness tracker and a smartwatch can feel like navigating a minefield. Do you need a full-blown smartwatch with apps, notifications and contactless payments? Or would a dedicated fitness tracker with exceptional battery life serve you better? And with prices ranging from £59 to over £700, how do you know which device offers the best value?

In this comprehensive guide, we've tested and compared the best fitness trackers and smartwatches available in the UK for 2025. Whether you're a casual gym-goer, a dedicated runner, or simply want to keep tabs on your daily health metrics, we've got a recommendation for you.

Fitness Tracker vs Smartwatch: Which Do You Need?

Before diving into specific recommendations, it helps to understand the key differences between these two categories of wearable.

Fitness Trackers

Fitness trackers are primarily designed to monitor your physical activity and health metrics. They typically feature a slim, lightweight band with a small display, and focus on tracking steps, heart rate, sleep, calories and exercise. Battery life is their standout advantage — many last 5 to 14 days on a single charge. They're generally more affordable than smartwatches, making them ideal if your primary goal is health and fitness monitoring without the bells and whistles.

Smartwatches

Smartwatches are essentially miniature computers on your wrist. They do everything a fitness tracker does, but add app support, phone notifications, music storage and playback, contactless payments, voice assistants and much more. The trade-off is battery life — most smartwatches need charging every 1 to 3 days. They're best suited to people who want a connected device that also tracks fitness, rather than a dedicated fitness device.

Our Top 8 Picks for 2025

1. Apple Watch SE (2nd Gen) — Best Smartwatch for iPhone Users on a Budget

Price: ~£219

The Apple Watch SE is the sweet spot in Apple's lineup — offering the core Apple Watch experience at a price that won't break the bank. It runs the same watchOS software as its pricier siblings, giving you access to the full App Store, Apple Pay, Siri, phone notifications, and seamless integration with your iPhone.

Fitness tracking is comprehensive: you get continuous heart rate monitoring, fall detection, crash detection, workout tracking for dozens of activities, and Apple's signature Activity Rings that gamify your daily movement goals. The watch also tracks sleep, though it lacks the advanced temperature sensing of the more expensive Apple Watch Series models.

The 40mm or 44mm OLED display is bright, sharp and responsive, with a Digital Crown for easy navigation. Build quality is excellent, with a swimproof design rated to 50 metres. The main compromise compared to the flagship Apple Watch is the lack of an always-on display and the absence of blood oxygen and ECG sensors.

Battery life is the familiar Apple Watch story — about 18 hours with typical use, meaning daily charging is necessary. If you're an iPhone user who wants a capable smartwatch without paying flagship prices, the SE is hard to beat.

2. Apple Watch Ultra 2 — Best Premium Smartwatch for Outdoor Adventures

Price: ~£699

The Apple Watch Ultra 2 is Apple's most rugged and capable smartwatch, designed for serious outdoor enthusiasts, endurance athletes and divers. Its 49mm titanium case is built to withstand extreme conditions, with water resistance to 100 metres, a depth gauge, water temperature sensor, and EN13319 certification for recreational diving to 40 metres.

The always-on display is the brightest Apple has ever made at 3,000 nits, ensuring readability in direct sunlight. Dual-frequency GPS (L1 + L5) provides the most accurate location tracking available on any smartwatch, making it superb for trail running, hiking and cycling in challenging environments.

Battery life is a significant step up from the standard Apple Watch, lasting up to 36 hours with normal use or 72 hours in Low Power Mode. While still not matching dedicated fitness watches from Garmin, it's a huge improvement for the Apple ecosystem. The customisable Action Button provides quick access to workouts, waypoints or any other function you assign to it.

The price is steep at £699, but for those who need a premium smartwatch that can handle outdoor adventures, extreme sports and everyday smart features equally well, the Ultra 2 is in a class of its own within the Apple ecosystem.

3. Samsung Galaxy Watch 7 — Best Smartwatch for Android Users

Price: ~£269 (40mm) / ~£299 (44mm)

If you're an Android user, the Samsung Galaxy Watch 7 is the best all-round smartwatch you can buy. Running Google's Wear OS with Samsung's One UI Watch overlay, it offers a polished, feature-rich experience with access to Google Play apps, Google Maps, Google Assistant, Google Wallet and Samsung Pay.

Health and fitness tracking is excellent. The Galaxy Watch 7 features Samsung's BioActive sensor, which combines optical heart rate, electrical heart signal and bioelectrical impedance analysis into a single chip. This enables heart rate monitoring, ECG readings, blood pressure tracking (with compatible Samsung phone), body composition analysis and advanced sleep coaching with sleep stages, blood oxygen levels and skin temperature monitoring.

The circular Super AMOLED display is gorgeous, with an always-on option, and the watch feels premium in the hand with its aluminium case and sapphire crystal glass. Samsung's software is intuitive, and the watch integrates beautifully with Samsung phones whilst also working well with other Android devices.

Battery life is roughly 30-40 hours depending on usage, which is a meaningful improvement over Apple Watch. The watch charges quickly via wireless charging and is swimproof to 50 metres.

4. Garmin Venu 3 — Best for Serious Health Tracking

Price: ~£390 (41mm) / ~£410 (45mm)

The Garmin Venu 3 bridges the gap between smartwatch and dedicated sports watch, offering a vibrant AMOLED display alongside Garmin's industry-leading health and fitness tracking. It's ideal for users who want deep health insights without sacrificing the visual appeal of a traditional smartwatch.

What sets the Venu 3 apart is Garmin's Health Snapshot feature, which records key health metrics in a single two-minute session: heart rate, heart rate variability, blood oxygen, respiration rate and stress. The watch also offers Body Battery energy monitoring, which tracks your body's energy reserves throughout the day, helping you optimise when to work out and when to rest. Sleep tracking is exceptionally detailed, with sleep stages, sleep score, nap detection, and a sleep coach that provides personalised recommendations.

For the first time in a Garmin wearable, the Venu 3 supports phone calls via the built-in speaker and microphone. You also get music storage for up to 500 songs, Garmin Pay for contactless payments, and smart notifications from your phone. Battery life is impressive at up to 14 days in smartwatch mode — vastly outperforming Apple and Samsung.

The trade-off is app support. Garmin's Connect IQ store has a fraction of the apps available on Apple or Google's platforms. But if health and fitness tracking is your primary motivation, the Venu 3 delivers more depth and accuracy than any competitor.

5. Fitbit Charge 6 — Best Fitness Tracker

Price: ~£99

The Fitbit Charge 6 is the best dedicated fitness tracker you can buy in the UK in 2025. At just £99, it packs an impressive array of features into a slim, comfortable band that you'll genuinely forget you're wearing — which is exactly what you want from a device designed for 24/7 health monitoring.

The Charge 6 brings back the side button that was missing from its predecessor, making navigation much easier. It features Google integration with Google Maps, Google Wallet and YouTube Music controls — a significant upgrade from previous Fitbit trackers. Built-in GPS means you can leave your phone behind on runs, and the tracker will accurately map your route and pace.

Health tracking is comprehensive for the price: continuous heart rate, blood oxygen monitoring, ECG app, Daily Readiness Score, stress management tools, sleep tracking with sleep stages and skin temperature monitoring. The Active Zone Minutes feature vibrates when you enter different heart rate zones during exercise, providing real-time feedback without needing to glance at the screen.

Battery life is excellent at 7 days with typical use, and the slim profile means it's comfortable for sleep tracking. The colour AMOLED touchscreen is small but clear, and the tracker is waterproof to 50 metres for swim tracking.

6. Garmin Forerunner 265 — Best for Runners

Price: ~£380 (42mm) / ~£400 (46mm)

If running is your primary sport, the Garmin Forerunner 265 is the gold standard. This GPS running watch combines Garmin's decades of sports tracking expertise with a stunning AMOLED display, delivering detailed training metrics that will help runners of all levels improve their performance.

The training features are where the Forerunner 265 truly excels. It offers Training Readiness scores that factor in sleep quality, recovery time, training load and HRV status to tell you whether your body is ready for a hard session or needs rest. Daily Suggested Workouts adapt to your fitness level and training history, providing structured sessions that progress over time. Race Predictor estimates your finish times for 5K, 10K, half-marathon and marathon distances based on your current fitness.

GPS accuracy is outstanding, using multi-band satellite positioning (GPS, GLONASS, Galileo) with SatIQ technology that intelligently switches between modes to balance accuracy and battery life. Running dynamics — including cadence, ground contact time, stride length and vertical oscillation — are available with a compatible chest strap or the Garmin Running Dynamics Pod.

Battery life is impressive at up to 13 days in smartwatch mode or 20 hours in GPS mode. The watch also supports music storage, Garmin Pay, and smart notifications, making it functional for everyday wear beyond training. PacePro provides real-time pacing guidance during races, accounting for course elevation to help you maintain an even effort.

7. Amazfit GTR 4 — Best Budget Smartwatch

Price: ~£149

The Amazfit GTR 4 offers a staggering amount of features for its price, making it the best budget smartwatch in the UK for 2025. At around £149, it undercuts the Apple Watch SE by £70 while offering many comparable features — and significantly better battery life.

The 1.43-inch AMOLED display is bright, colourful and responsive, protected by hardened glass. The circular stainless steel case gives it a classic watch appearance that looks more premium than its price suggests. Over 150 sport modes cover virtually any activity you can think of, from running and swimming to cricket, badminton and even e-sports.

Health tracking includes 24/7 heart rate monitoring, blood oxygen saturation, stress tracking, sleep analysis with REM/light/deep stages, and a PAI (Personal Activity Intelligence) score that simplifies your overall health data into a single meaningful number. The built-in dual-band GPS provides accurate route tracking without needing your phone, and the watch is waterproof to 50 metres.

Battery life is the standout feature: up to 14 days in smartwatch mode with typical use, or 24 days in battery-saver mode. You also get Bluetooth calling via the built-in microphone and speaker, music storage, Amazon Alexa integration, and offline voice commands via Zepp OS. The watch works with both Android and iOS.

The compromises at this price point are in software polish and app ecosystem. Zepp OS is functional but less refined than watchOS or Wear OS, and third-party app support is limited. Notification handling is basic — you can read messages but responses are limited. Despite these drawbacks, the hardware value is extraordinary.

8. Google Pixel Watch 3 — Best for Google Ecosystem

Price: ~£349 (41mm) / ~£389 (45mm)

The Google Pixel Watch 3 is Google's most refined smartwatch, offering a beautifully designed, fully integrated Wear OS experience that's particularly appealing to users already invested in Google's ecosystem. Its distinctive domed, bezel-less design sets it apart visually from every other smartwatch on the market.

The Pixel Watch 3 runs a clean, stock version of Wear OS 5 with deep Google integration. You get Google Maps with turn-by-turn navigation on your wrist, Google Wallet for contactless payments, YouTube Music for offline listening, Google Assistant, Gmail notifications and seamless connectivity with Pixel phones and other Android devices. Fitbit's health tracking platform is fully integrated, providing detailed workout tracking, sleep analysis, Daily Readiness Score and heart rate monitoring.

The 45mm model is a welcome addition, offering a larger and brighter AMOLED display that's easier to read during workouts. The always-on display is vibrant, and the Corning Gorilla Glass 5 and recycled aluminium case feel premium in the hand. GPS tracking uses dual-band positioning for improved accuracy, and the watch is waterproof to 50 metres.

Battery life is the main weakness, lasting roughly 24 hours with the always-on display enabled — though this is an improvement over earlier Pixel Watch models. Fast charging brings the watch from 0 to 50% in about 30 minutes, which helps mitigate the daily charging requirement.

Full Comparison Table

Feature	Apple Watch SE	Apple Watch Ultra 2	Galaxy Watch 7	Garmin Venu 3	Fitbit Charge 6	Forerunner 265	Amazfit GTR 4	Pixel Watch 3
Type	Smartwatch	Smartwatch	Smartwatch	Smartwatch	Fitness Tracker	Sports Watch	Smartwatch	Smartwatch
Price	~£219	~£699	~£269	~£390	~£99	~£380	~£149	~£349
Display	OLED	OLED (AOD)	AMOLED (AOD)	AMOLED (AOD)	AMOLED	AMOLED (AOD)	AMOLED (AOD)	AMOLED (AOD)
Battery Life	~18 hours	~36 hours	~40 hours	~14 days	~7 days	~13 days	~14 days	~24 hours
GPS	Yes	Dual-band	Dual-band	Multi-band	Yes	Multi-band	Dual-band	Dual-band
Heart Rate	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes
ECG	No	Yes	Yes	No	Yes	No	No	No
Blood Oxygen	No	Yes	Yes	Yes	Yes	Yes	Yes	Yes
NFC Payments	Apple Pay	Apple Pay	Samsung/Google Pay	Garmin Pay	Google Wallet	Garmin Pay	No (UK)	Google Wallet
Water Resistance	50m	100m	50m	50m	50m	50m	50m	50m
Phone Compatibility	iPhone only	iPhone only	Android only	Android + iPhone	Android + iPhone	Android + iPhone	Android + iPhone	Android only
Best For	iPhone users	Outdoor athletes	Android users	Health tracking	Budget fitness	Runners	Budget smartwatch	Google fans

Key Health Features Explained

Modern wearables track a dizzying array of health metrics. Here's what the most important ones actually mean and how useful they are in practice.

Heart Rate Monitoring

All devices on our list offer continuous optical heart rate monitoring using LED sensors on the underside of the watch. This data underpins calorie counting, exercise intensity tracking and resting heart rate trends. Wrist-based optical sensors are generally accurate to within 3-5 beats per minute during steady-state exercise, though they can struggle with high-intensity interval training or activities involving a lot of wrist movement. For maximum accuracy during intense workouts, a chest strap heart rate monitor (like the Garmin HRM-Pro Plus, around £80) remains the gold standard.

Blood Oxygen (SpO2) Monitoring

Blood oxygen saturation measures the percentage of oxygen being carried by your red blood cells. Normal levels are typically between 95% and 100%. Consistently low readings could indicate respiratory issues, sleep apnoea or altitude-related problems. Most wearables measure SpO2 using red and infrared LEDs.

ECG (Electrocardiogram)

An ECG measures the electrical activity of your heart and can detect irregular heart rhythms such as atrial fibrillation (AFib). The Samsung Galaxy Watch 7 and Fitbit Charge 6 both offer this feature. While useful for screening, a wearable ECG is a simplified version of the 12-lead ECG used in clinical settings and should be treated as a tool for awareness rather than diagnosis.

Sleep Tracking

All devices on our list track sleep, but the depth and accuracy varies considerably. The best sleep trackers — Garmin and Fitbit in particular — detect sleep stages (light, deep and REM), track blood oxygen during sleep, monitor skin temperature changes, and provide a sleep score along with actionable recommendations. The Garmin Venu 3 is particularly impressive, detecting naps and providing a morning report that includes Body Battery recharge data and sleep quality insights.

Stress Tracking

Stress scores are calculated using heart rate variability (HRV) — the variation in time between consecutive heartbeats. Higher HRV generally indicates a more relaxed state, while lower HRV suggests stress. Garmin, Fitbit and Samsung all offer stress tracking with guided breathing exercises to help you manage stress levels throughout the day.

Battery Life: What to Expect

Battery life is often the deciding factor when choosing between a smartwatch and a fitness tracker, or between competing brands. Here's what you can realistically expect from each device in our lineup.

The Charging Reality

Manufacturer-quoted battery life figures are typically measured under idealised conditions — limited GPS use, no always-on display, minimal notifications. In real-world use, expect roughly 70-80% of the claimed battery life. An Apple Watch SE quoted at 18 hours will typically last a full day with moderate use, but heavy GPS usage or lots of notifications can drain it significantly faster.

The Garmin devices stand out dramatically in battery life. The Venu 3 and Forerunner 265 both last well over a week in our testing, even with daily GPS workouts and continuous health monitoring. This means you can track sleep without worrying about finding a charging window — a genuine advantage over Apple, Samsung and Google watches that need nightly or daily charging.

Charging speeds have improved across the board. Most devices reach 50% in 20-30 minutes, and a full charge takes 1-2 hours. If you're committed to an Apple Watch or Samsung Galaxy Watch, a quick 20-minute charge while you shower in the morning is usually enough to get through the day with sleep tracking at night.

Sport-Specific Recommendations

Different sports and activities have different tracking requirements. Here are our recommendations based on specific use cases.

Running

The Garmin Forerunner 265 is the clear winner for dedicated runners. Its training load analysis, race predictions, PacePro pacing and multi-band GPS are purpose-built for the sport. For casual runners on a budget, the Fitbit Charge 6 offers built-in GPS and heart rate zone tracking at a fraction of the price.

Gym and Strength Training

The Apple Watch SE or Samsung Galaxy Watch 7 excel for gym use, with automatic exercise detection, rep counting and a wide range of tracked activities. The Apple Watch's Activity Rings and Samsung's body composition analysis add motivational elements to your training.

Swimming

All devices on our list are waterproof to at least 50 metres, but the Apple Watch Ultra 2 is the standout for swimmers and water sports enthusiasts with its 100m rating and depth gauge. For pool swimming on a budget, the Garmin Venu 3 offers accurate lap counting, stroke detection and SWOLF efficiency scoring.

Cycling

The Garmin Forerunner 265 and Garmin Venu 3 both support cycling profiles with advanced metrics. For the most comprehensive cycling experience, Garmin devices can connect to external sensors including power meters, speed sensors and cadence sensors via ANT+ — a protocol that Apple Watch and Samsung Galaxy Watch don't support.

Hiking and Outdoor Adventures

The Apple Watch Ultra 2 is purpose-built for outdoor adventures with its rugged construction, dual-frequency GPS, compass, altimeter and Backtrack feature for retracing your steps. If you're an Android user, the Garmin Venu 3 offers comparable outdoor features with significantly better battery life.

General Health and Wellness

If your primary goal is simply monitoring your daily health — steps, heart rate, sleep and stress — the Fitbit Charge 6 is the most cost-effective option. It tracks everything you need without the distraction of apps and notifications, and its 7-day battery life means you never miss a night of sleep data.

Compatibility Considerations

Before purchasing any wearable, check that it's compatible with your smartphone. This is one of the most common mistakes buyers make.

Apple Watch (all models): Requires an iPhone. There is no Android compatibility whatsoever. If you use an Android phone, do not buy an Apple Watch.

Samsung Galaxy Watch 7: Works with Android phones only. While technically functional with non-Samsung Android phones, some advanced features (like blood pressure monitoring and ECG) require a Samsung Galaxy phone to function.

Google Pixel Watch 3: Android only. Works best with Pixel phones but is compatible with any Android device running Android 9.0 or later.

Garmin watches: Compatible with both Android and iPhone. This cross-platform compatibility is a significant advantage for users who switch between phone ecosystems or who want a wearable that isn't locked to a specific phone brand.

Fitbit Charge 6: Works with both Android and iPhone. Google's acquisition of Fitbit has brought Google services to the platform whilst maintaining iOS compatibility.

Amazfit GTR 4: Compatible with both Android and iPhone via the Zepp app. Full functionality is available on both platforms.

Subscription Services: What's Free and What's Not

Several wearable platforms now offer premium subscription services that lock certain features behind a paywall. It's important to understand what you're getting for free and what requires an ongoing payment.

Fitbit Premium (£7.99/month): The Charge 6 provides core health and fitness tracking for free, but advanced features like Daily Readiness Score, detailed sleep analysis, wellness reports and guided workouts require a Fitbit Premium subscription. New Fitbit devices include 6 months free.

Samsung Health: Most health features are free, though some advanced insights and challenges may require Samsung Health integration with third-party apps.

Garmin Connect: Garmin's entire platform is completely free with no subscription required. All training plans, health insights, analysis tools and features are included at no additional cost. This is one of Garmin's strongest selling points.

Apple Fitness+: While Apple Watch works perfectly without it, Apple Fitness+ (£9.99/month) adds guided workouts, meditations and integration with your watch's metrics. It's optional and not required for any health tracking features.

Frequently Asked Questions

Are fitness trackers worth it in 2025?

Yes, particularly if you're looking for an affordable way to monitor your health and activity levels. Modern fitness trackers offer accurate heart rate monitoring, sleep tracking, GPS and much more at a fraction of the price of a smartwatch. The Fitbit Charge 6 at £99 is arguably the best health-tracking bargain in consumer electronics.

Do I need a smartwatch if I already have a smartphone?

A smartwatch adds convenience rather than entirely new functionality. Being able to glance at notifications, control music, check your heart rate and pay for coffee without reaching for your phone is genuinely useful once you get used to it. Whether that convenience justifies the price is a personal decision.

How accurate are wrist-based heart rate monitors?

For resting heart rate and steady-state cardio, modern optical sensors are generally accurate to within 3-5 beats per minute. Accuracy decreases during high-intensity interval training, activities with lots of wrist movement, or in very cold conditions. For clinical-grade accuracy during exercise, a chest strap monitor is recommended.

Can I shower with my fitness tracker or smartwatch?

All devices on our list are rated for water resistance and can handle showers. However, most manufacturers recommend avoiding hot water and soap, as these can degrade the water-resistant seals over time. Swimming and rain are fine; hot tubs and saunas are generally not recommended.

Which smartwatch has the best battery life?

The Garmin Venu 3 and Amazfit GTR 4 both last around 14 days in smartwatch mode, dwarfing the 18-24 hour battery life of Apple Watch and Google Pixel Watch. If battery life is your top priority, Garmin and Amazfit are the clear winners.

Is the Apple Watch Ultra 2 worth the extra money?

Only if you genuinely need its rugged construction and advanced outdoor features. For the average user, the Apple Watch SE provides 90% of the functionality at less than a third of the price. The Ultra 2 is best suited to outdoor enthusiasts, endurance athletes, divers and those who need exceptional durability and battery life within the Apple ecosystem.

Final Verdict

The best wearable for you depends entirely on your priorities, phone ecosystem and budget. Here's our summary:

Best overall smartwatch for iPhone users: The Apple Watch SE (2nd Gen) at £219 offers the best balance of features, quality and price within the Apple ecosystem. It does everything most people need without the premium price tag.

Best overall smartwatch for Android users: The Samsung Galaxy Watch 7 at £269 provides the most complete Android smartwatch experience with excellent health tracking, a gorgeous display and full Wear OS app support.

Best fitness tracker: The Fitbit Charge 6 at £99 is unbeatable for pure health and fitness tracking on a budget. It offers built-in GPS, ECG, blood oxygen monitoring and 7-day battery life in a slim, comfortable package.

Best for serious health tracking: The Garmin Venu 3 at £390 delivers the deepest health insights of any wearable, with 14-day battery life, Body Battery, advanced sleep tracking and cross-platform compatibility.

Best for runners: The Garmin Forerunner 265 at £380 is the ultimate running companion with training load analysis, race predictions, multi-band GPS and 13-day battery life.

Best budget smartwatch: The Amazfit GTR 4 at £149 packs an astonishing amount of features — AMOLED display, dual-band GPS, Bluetooth calling, 14-day battery — into an incredibly affordable package.

Whatever you choose, a wearable device can be a powerful motivational tool for improving your health and fitness. The key is finding one that fits your lifestyle, works with your phone, and sits comfortably within your budget. Use PriceDetective to compare prices across UK retailers and find the best deal on your chosen device.