Fitbit vs Apple Watch: Which Should You Buy in 2026?

Buy an Apple Watch if you have an iPhone and want a real smartwatch: apps, Apple Pay, the widest health feature list and no subscription for the core data. Buy a Fitbit if you're on Android, you want close to a week between charges, or your budget stops under £100. That's the whole decision for most people, and the iPhone question settles it before anything else does.

Everything below is the detail behind that answer, model by model, so you can see where the line falls for you.

The line-ups you're actually choosing between

Apple's UK store lists three watches: the SE 3 from £219, the Series 12 from £369 and the Ultra 4 from £749. Apple's own Apple Watch comparison page has the full feature breakdown.

On the Fitbit side we're sticking to the three models we've reviewed in depth. The Inspire 3 is a slim band at around £60 on Amazon. The Charge 6 adds built-in GPS and an ECG app for around £105 (Google's own store charges £139.99, so Amazon is the cheaper route). The Versa 4 is the watch-shaped one at around £179.

So the price overlap is tiny. The dearest Fitbit here costs less than the cheapest Apple Watch, which tells you the two brands aren't really chasing the same buyer.

Fitbit vs Apple Watch at a glance

	Fitbit (Inspire 3, Charge 6, Versa 4)	Apple Watch (SE 3, Series 12, Ultra 4)
Price	Around £60 to £179 on Amazon UK	£219 to £749 on Apple's UK store
Phone	iPhone (iOS 16.4+) or Android (11+)	iPhone 11 or later only
Battery (claimed)	Inspire 3 up to 10 days, Charge 6 up to 7 days, Versa 4 6+ days	SE 3 18 hours, Series 12 24 hours, Ultra 4 50 hours
GPS	Built in on Charge 6 and Versa 4; Inspire 3 uses your phone	Built in on all; L1 on Series 12, dual-frequency L1 + L5 on Ultra 4
ECG	Charge 6 only	Series 12 and Ultra 4, not SE 3
Blood oxygen	SpO2 on all three	Series 12 and Ultra 4, not SE 3
Payments	Google Wallet on Charge 6 and Versa 4	Apple Pay on all
Third-party apps	None	Full App Store
Subscription	Google Health Premium from £7.99/month for Readiness and coaching	None needed for core data; Fitness+ optional at £9.99/month

Battery life: Fitbit wins, and it isn't close

Google rates the Charge 6 at up to seven days and the Versa 4 at 6+ days. Both drop to roughly three or four days if you switch on the always-on display or log GPS runs most days, which is still a long way ahead of Apple. The Inspire 3 goes furthest at up to 10 days because it has no GPS radio to feed.

Apple rates the SE 3 at 18 hours and the Series 12 at 24 hours. Low Power Mode stretches those to 32 and 38 hours, but in real life you're charging every day. Fast charging makes that easier than it sounds: Apple says 15 minutes on the puck gives the Series 12 up to 12 hours, so a top-up during breakfast keeps sleep tracking going overnight. The Ultra 4, at up to 50 hours (84 in Low Power Mode), is the only Apple Watch that survives a weekend.

If you've abandoned sleep tracking before because the watch was always flat at bedtime, that's a strong vote for Fitbit.

Price and the subscription question

The upfront cost favours Fitbit heavily. A Charge 6 at around £105 costs less than half an SE 3, and it brings GPS, an ECG app and Google Wallet with it.

The running cost is where Fitbit claws some of that back for Google. The Fitbit app is now the Google Health app, and Google sells Google Health Premium from £7.99 a month on its Google Health Premium page, with three months included when you buy a new Fitbit. Premium unlocks the Daily Readiness score, the detailed stress breakdown, most guided content and Google's Gemini-based coaching. The free tier still covers steps, heart rate, sleep stages, GPS workouts and Active Zone Minutes, and plenty of owners never pay.

Apple doesn't gate any of its tracking. Sleep score, Vitals, the ECG app, cardio fitness and (on the Series 12 and Ultra 4) the new Recovery features come with the watch. Apple Fitness+ costs £9.99 a month after the trial, but that's a library of guided workouts, not a key to your own data.

Do the sums before you decide. A Charge 6 plus two years of Premium at £7.99 a month comes to about £275 after the free three months, which is more than an SE 3 bought outright. Skip Premium and the Fitbit stays far cheaper.

Accuracy: closer than the price gap suggests

Most of the independent research uses older models, so treat it as a guide to how each brand's sensors behave rather than a verdict on this year's hardware.

The best-known head-to-head is a Stanford study of seven wrist devices, including an Apple Watch and a Fitbit Surge, tested against chest-strap telemetry and indirect calorimetry (Shcherbina et al., 2017). The Apple Watch had the lowest overall error for both heart rate and energy expenditure. The more useful finding for anyone buying either brand: no device estimated calories to within 20%, so don't plan meals around the number on your wrist.

A 2021 free-living study had people wear a Fitbit Charge 2, Fitbit Alta and Apple Watch 2 for 24 hours (Bai et al., 2021). Both the Charge 2 and the Apple Watch gave reasonable heart rate estimates, with error across the monitors ranging from 4% to 16%, and all three counted steps fairly accurately. Accuracy was better at rest than during harder activity, which is true of every optical wrist sensor.

The practical upshot is that you won't notice a meaningful accuracy difference day to day. If you train by heart rate zones and want precise numbers, pair either brand with a chest strap.

GPS and running

The Charge 6 and Versa 4 have built-in GPS plus GLONASS, so you can leave the phone at home and still get pace, distance and a route map afterwards. Our Charge 6 review notes it can take 20 to 40 seconds to lock on, and neither Fitbit shows a map or breadcrumb trail while you run. The Inspire 3 has no GPS chip; it borrows your phone's location.

Every Apple Watch has GPS. The Series 12 uses precision L1 GPS and the Ultra 4 adds the L5 band for better tracks among tall buildings and trees. You also get live pace, heart rate zones and custom workouts on a screen big enough to read mid-run, and the SE 3 has 64GB of storage for offline music and podcasts. The Versa 4 has no music storage at all.

For casual runners either brand works. Anyone training for a half or full marathon should look past both; Garmin's watches last days on a charge and work with Android or iPhone, and our best Garmin watch guide covers which one to pick.

Apps, payments and the smartwatch side

This is Apple's biggest lead. The Apple Watch runs a full App Store, answers calls, replies to messages, works with Apple Pay everywhere contactless is accepted, and handles Siri requests on the wrist.

Fitbit went the other way. Google removed third-party apps and Wi-Fi from the Versa 4 compared with the Versa 3, so you get Google Wallet, Google Maps directions, notifications and Bluetooth calls, and that's roughly it. The Charge 6 and Inspire 3 are trackers first; they show notifications, but nobody buys them to reply to messages.

If you'd use a smartwatch for more than fitness, there's no real contest here.

Health features

Apple's list is longer, especially on the Series 12. It has the ECG app, blood oxygen, irregular rhythm notifications, hypertension notifications, sleep apnoea notifications, sleep score and the Vitals app tracking overnight heart rate, respiratory rate, wrist temperature, blood oxygen and HRV. The SE 3 keeps sleep score, sleep apnoea notifications and wrist temperature but drops ECG, blood oxygen and hypertension notifications.

Fitbit has always been strong on sleep, and its Sleep Score and sleep stages are free. The Charge 6 has an ECG app and an EDA Scan app for stress, and all three Fitbits track SpO2. The Versa 4 doesn't have ECG, which is an odd gap given the cheaper Charge 6 does.

Who should buy which

• Apple Watch SE 3 (£219): iPhone owners who want a proper smartwatch without paying Series 12 money. Read our SE 3 review for what it leaves out.
• Apple Watch Series 12 (from £369): iPhone owners who want ECG, blood oxygen, hypertension notifications and the Recovery features, and don't mind charging nightly.
• Apple Watch Ultra 4 (from £749): hikers, triathletes and anyone who needs two days of battery and dual-frequency GPS.
• Fitbit Inspire 3 (around £60): the cheapest way to get decent sleep, step and heart rate tracking, on any phone.
• Fitbit Charge 6 (around £105): the best value here. GPS, ECG, Google Wallet and a week of battery for about half the price of an SE 3.
• Fitbit Versa 4 (around £179): Android users who want a bigger screen and Bluetooth calls, and can live without third-party apps.

Android users can skip half this list, since no Apple Watch will pair with their phone. If you're torn between a screenless band and an Apple Watch instead, our WHOOP vs Apple Watch comparison covers that choice.

Our verdict

For an iPhone owner with £219 to spend, the Apple Watch SE 3 is the better product: it's a full smartwatch, it needs no subscription, and Apple's health features are broader. For everyone else, and for anyone who resents charging a watch every day, the Fitbit Charge 6 is the one to buy. It costs well under half as much, tracks the things most people actually look at, and runs for most of a week.

Check the Fitbit Charge 6 price on Amazonaround £105 Check the Apple Watch SE 3 price on Amazonaround £196

Prices on Amazon UK move often, so check the current figure before you buy.

Recommended reads

• Fitbit Charge 6 review
• Apple Watch SE 3 review
• Fitbit Versa 4 review
• WHOOP vs Apple Watch
• Best Garmin watch in the UK