The smartwatch to buy now

The best smart watches in the UK in September 2026 are the ones that match your phone. The Apple Watch Series 12 is the best smartwatch for iPhone owners, the Samsung Galaxy Watch9 is the best for Samsung Galaxy phones, and the Google Pixel Watch 5 is the best for Pixel and other Android phones. The Garmin Instinct 3 AMOLED is the pick for battery life at up to 18 days per charge, and the Amazfit Active 2 is the best smartwatch under £150.

Apple announced the Apple Watch Series 12 and Apple Watch Ultra 4 on 9 September 2026, and both went on sale on 18 September. Google put the Pixel Watch 5 on sale on 20 August 2026, and Samsung released the Galaxy Watch9 on 7 August 2026. That makes this the first month in which all three flagship platforms have a current model on Amazon UK at the same time.

Which smartwatches work with iPhone and which with Android?

The Apple Watch works only with an iPhone, the Galaxy Watch9 and Pixel Watch 5 work only with Android, and the Garmin and Amazfit picks work with both. That single fact removes half the shortlist before price or battery come into it, so Compare Electronic's compatibility matrix comes first.

Two points in the matrix catch buyers out. Samsung ties the ECG and blood pressure features on the Galaxy Watch9 to its Samsung Health Monitor app, which runs only on Galaxy phones, so a Pixel owner loses two headline health tools. Garmin watches paired with an iPhone show notifications but cannot send quick replies, a limit Apple places on third-party watches rather than one Garmin chooses.

1. Apple Watch Series 12 - best smartwatch for iPhone

The Apple Watch Series 12 is the best smartwatch for iPhone owners because no rival gets the same access to iOS. The 42 mm GPS model costs £369 on Amazon UK at the time of writing (September 2026), and the 46 mm model costs £419. Apple builds the Series 12 around the S11 chip and a new Health Sensing System that combines optical and electrical heart sensors, and Apple says the Series 12 now samples heart rate every five seconds through the day.

The Apple Watch Series 12 adds a daily readiness score that reads training load, vitals and sleep score, which closes the biggest gap to Garmin and Whoop. Apple rates the Series 12 at 24 hours of normal use and 38 hours in Low Power Mode, and Apple says 15 minutes on the charger adds up to 12 hours. The display peaks at 2,000 nits, and the case is water resistant to 50 m.

The Apple Watch Series 12 suits iPhone owners who want the widest app support, ECG, hypertension notifications and Apple Pay in one watch. Buyers who want multi-day battery on an iPhone should look at the Ultra 4 comparison further down, or at the Garmin Instinct 3 AMOLED. The previous Apple Watch Series 11 costs £279 on Amazon UK at the time of writing, which is £90 less, and remains a sound buy for anyone who does not need the new heart sensor.

2. Samsung Galaxy Watch9 - best smartwatch for Samsung phones

The Samsung Galaxy Watch9 is the best smartwatch for owners of a Samsung Galaxy phone. The 40 mm Bluetooth model costs £349 on Amazon UK at the time of writing (September 2026), and the 44 mm model costs £379. The Galaxy Watch9 runs on Qualcomm's 3 nm Snapdragon Wear Elite chip with 2 GB of RAM and 32 GB of storage, and the display reaches 3,000 nits, 1,000 nits brighter than the Apple Watch Series 12.

Samsung Health on the Galaxy Watch9 covers ECG, blood pressure, sleep coaching, an Energy Score for daily readiness and a running coach, and Samsung charges no subscription for any of it. Samsung rates the 40 mm Galaxy Watch9 at up to 30 hours with the always-on display enabled from a 390 mAh battery. Senses.se titled its review "Fast Performance but Flawed Battery", and the Galaxy Watch9 is a nightly-charge watch in practice.

The Samsung Galaxy Watch9 suits Galaxy phone owners who want the full health suite and Gemini on the wrist. Owners of other Android phones lose ECG and blood pressure, which makes the Pixel Watch 5 the stronger buy outside Samsung's ecosystem.

3. Google Pixel Watch 5 - best smartwatch for Pixel and Android

The Google Pixel Watch 5 is the best smartwatch for Pixel owners and the best Wear OS watch for Android phones outside Samsung's range. The 41 mm Wi-Fi model costs £369 on Amazon UK at the time of writing (September 2026), and the 45 mm model costs £399. Google moved the Pixel Watch 5 to a Snapdragon W5 Gen 2 Accelerated chip, raised the RAM from 2 GB to 3 GB and doubled storage to 64 GB.

Google rates the 41 mm Pixel Watch 5 at 30 hours with the always-on display and 48 hours in Battery Saver, from a 332 mAh cell, and the 45 mm model at 40 hours. The display peaks at 3,000 nits, the case carries IP68 and 5ATM ratings, and the 41 mm body weighs 31 g without the band. Fitbit-derived health tracking, including ECG and sleep staging, runs through the Google Health app.

The Google Pixel Watch 5 suits Android owners who want Gemini, the cleanest version of Wear OS and Fitbit's health tracking without tying themselves to Samsung. Galaxy phone owners get more from the Galaxy Watch9 for £20 less.

4. Garmin Instinct 3 AMOLED - best battery life

The Garmin Instinct 3 AMOLED is the best smartwatch for battery life. Garmin rates the 45 mm Instinct 3 AMOLED at up to 18 days in smartwatch mode, 7 days with the always-on display enabled and 32 hours of continuous GPS. The 45 mm model costs £269 on Amazon UK at the time of writing (September 2026), £100 less than the Apple Watch Series 12.

The Garmin Instinct 3 AMOLED pairs a 1.2-inch AMOLED screen with multi-band GPS, a built-in LED torch with a red-light mode, Garmin Pay and a 100 m water rating. The case weighs 53 g and measures 14.9 mm thick, so the Instinct 3 AMOLED wears larger than the flagship smartwatches, and it has no music storage, no ECG and no third-party app store to speak of.

The Garmin Instinct 3 AMOLED suits runners, hikers and anyone who hates a nightly charge, on either iPhone or Android. Buyers who want apps, voice assistants and contactless payments on every bank should stay with the platform watches above.

5. Amazfit Active 2 - best smartwatch under £150

The Amazfit Active 2 is the best smartwatch under £150. The 44 mm Amazfit Active 2 costs £129.90 on Amazon UK at the time of writing (September 2026), about a third of the price of the Apple Watch Series 12. Amazfit rates the Active 2 at up to 10 days per charge, and the 1.32-inch AMOLED display peaks at 2,000 nits, matching the Apple Watch Series 12.

The Amazfit Active 2 includes built-in GPS with free offline maps, heart rate, blood oxygen and sleep tracking, 5ATM water resistance and a 29.5 g body. The Zepp app is free and works on both iPhone and Android. The trade-offs are a small third-party app library and no ECG.

The Amazfit Active 2 suits first-time smartwatch buyers and anyone who wants a week of battery without paying Garmin prices.

Best smartwatch UK 2026 spec sheet

Rated battery figures are each manufacturer's own: Apple and Google quote typical use with the always-on display, Samsung quotes the always-on display figure, and Garmin and Amazfit quote typical smartwatch use.

Which smartwatch has the best battery life for the money?

The Amazfit Active 2 gives the most battery per pound at £12.99 per day of rated battery life, with the Garmin Instinct 3 AMOLED close behind at £14.94. The table below is Compare Electronic's price-per-day breakdown: the Amazon UK price divided by the manufacturer's rated battery life in days, plus how many full charges a year that rating implies.

The spread is 28 to 1. A Garmin Instinct 3 AMOLED owner charges about 20 times a year, and an Apple Watch Series 12 owner charges 365 times. With the always-on display enabled, Garmin's rating falls to 7 days, which still works out at £38.43 per day, seven times better value than any of the flagship smartwatches. The flagships trade battery for apps, payments on every bank and voice assistants, so this metric decides the purchase only for buyers who rank endurance first.

Is the Apple Watch Ultra 4 worth £380 more than the Series 12?

The Apple Watch Ultra 4 is worth the extra £380 only for iPhone owners who need two-day battery, diving or satellite messaging. The Apple Watch Ultra 4 costs £749 on Amazon UK at the time of writing (September 2026), and every Ultra 4 includes cellular. Here is what the extra £380 buys, line by line:

Both watches share the S11 chip, so the Apple Watch Ultra 4 is not faster. The Apple Watch Series 12 suits most iPhone owners, and the Ultra 4 suits hikers, divers and triathletes who wear the watch for a full weekend away from a charger.

Do any of these smartwatches need a subscription?

No smartwatch on this list needs a subscription to track health or workouts. Samsung Health on the Galaxy Watch9 has no paid tier, and the Garmin Connect and Zepp apps are free. Google sells an optional Google Health Premium tier at £7.99 a month or £79.99 a year for coaching on the Pixel Watch 5, and Apple Fitness+ is an optional workout service for Apple Watch owners. Over three years, Google Health Premium on annual billing adds up to £239.97 to the cost of a Pixel Watch 5, which is worth factoring in before comparing it with the subscription-free Galaxy Watch9. Fitness trackers with compulsory memberships are covered in Best fitness tracker UK 2026.

What should UK buyers check before ordering a smartwatch?

• Charger in the box:all five picks ship with a USB-C charging cable or puck and none includes a UK 3-pin plug. The Apple Watch Series 12 needs a 20 W or faster USB-C adapter to hit Apple's 15-minute, 12-hour fast-charge claim.
• Case size: the prices quoted here are for the smaller case of each model. The larger case costs £50 more on the Apple Watch Series 12, £30 more on the Galaxy Watch9 and Pixel Watch 5.
• Returns: the Consumer Rights Act 2015 gives 30 days to reject a faulty smartwatch for a full refund, and Amazon UK accepts most change-of-mind returns within 30 days.
• Contactless payments: Apple Pay, Google Wallet, Samsung Wallet and Garmin Pay each support a different list of UK banks, so check your bank before relying on the watch at a till.

Verdict: which are the best smart watches to buy?

The Apple Watch Series 12 is the best smartwatch in the UK for iPhone owners, and nothing else on the market gets the same access to iOS. The Samsung Galaxy Watch9 is the best smartwatch for Samsung Galaxy owners at £349, and the Google Pixel Watch 5 is the best for Pixel and other Android phones at £369. The Garmin Instinct 3 AMOLED wins on battery at up to 18 days, and the Amazfit Active 2 is the best smartwatch under £150 at £129.90. For earbuds to pair with the watch, see Best wireless earbuds UK 2026, and for phones, see Best phone UK autumn 2026.