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22 June 2021

How to buy the best Fitbit fitness tracker

Our tests have found some brilliant Fitbit fitness trackers, but they’ve also revealed Fitbit trackers that aren’t up to scratch. Read on to find out more.
Christina Woodger
Fitbit-Charge-3 advice
Fitbit offers plenty of choice: trackers such as the Fitbit Inspire 2, children's trackers such as the Fitbit Ace 2 and smartwatches such as the Fitbit Versa. The best Fitbit devices accurately log your steps, are a breeze to use and are comfortable to wear. 

Whether you want a simple tracker for everyday use, or something more advanced with a heart-rate monitor and smart notifications, we've tested a Fitbit tracker for you. If you simply want to find out which models aced our tests, head to our list of best fitness trackers.

But, we’ve also found some Fitbit activity trackers that lagged behind when it comes to accuracy. We’ve uncovered Fitbit devices that reported double the number of calories burned - meaning you’ll have burned half as many calories as you think - and overstated step count by more than 30%. 

Only logged-in Which? members can view our recommendations in the table below. If you’re not yet a member, you can get instant access by joining Which?.

Best Fitbit fitness trackers

  • 82%

    It tracks many metrics accurately, it's easy to use and it's comfortable to wear, so you won't be tempted to give up on it and stick it in a drawer after a few weeks' of use. It has built-in GPS, a heart rate monitor, sleep-tracking, a pulse oximetry sensor and more. The only annoyance is that the screen can be hard to read when you're exercising outside on a sunny day.

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    First month only £5, then £9.99 per month, cancel any time

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  • 77%

    A great tracker for those who want to keep an eye on daily activity (rather than those who are super-serious about sports and want detailed metrics). It records steps, distance travelled and heart rate accurately, it's waterproof for use in the swimming pool, it looks attractive and it's comfortable enough to keep on your wrist all day. It doesn't have built-in GPS, though - so you'll need to take your phone out with you for it to track your running route.

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    First month only £5, then £9.99 per month, cancel any time

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  • 73%

    We love this fitness tracker. It tracks steps, distance and heart rate accurately, it's comfortable to wear, it's intuitive to use and it's waterproof for wearing in the pool. It doesn't have GPS, though, which is disappointing - meaning you'll need to keep your phone on you if you want it to track your running or cycling route.

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Table last updated June 2021

Fitbit fitness tracker alternatives

If a Fitbit fitness or activity tracker isn't for you, or you couldn't find what you were looking for in the table above, then don't despair. We've tested plenty of accurate and comfortable devices from other brands, including smartwatches and activity trackers from Garmin, Huawei and Samsung

For more on what to spend, and what features to look for, find out more about how to buy the best fitness tracker.

How we test Fitbit fitness and activity trackers

Our tough tests put each fitness watch or activity tracker through its paces. We check the accuracy of step, distance and heart-rate tracking in different scenarios. This ranges from a routine of daily tasks, such as loading or unloading the dishwasher and carrying the shopping, to more strenuous activities. This means we can tell you the fitness trackers that accurately measure your steps and those that don’t.

And we don’t stop there. We know a tracker will be useless if it’s so uncomfortable you’re reluctant to wear it, so we assess how comfortable each one is during exercise and for daily life.

We’ve put several Fitbit trackers through their paces in our lab tests – if the product you're looking for isn't in the table above then head over to our Fitbit fitness tracker reviews.

And to find out how reliable Fitbit trackers are compared to those from other brands, check out our page on the most reliable fitness tracker brands.