The Best Fitbits
How We Found the Best Fitbits
3 Weeks of testing
9 Fitbits evaluated
3 Top Picks
The Best Fitbits
The best Fitbit for you will comfortably and accurately track your vital signs and movements while blending seamlessly into your lifestyle. We brought in every Fitbit and their most popular accessories and tested them over three weeks to find out which ones combine reliable statistics and easy style for a fitness tracker you’ll love.
How We Chose the Best Fitbits
Whether you want a beat on how effective your workout was in terms of calories burned and distance traveled, or you just want to check your heart rate periodically and take note of your step count for the day — there’s a Fitbit with the ideal functionality for you. This is why we tested for a range of functions, because we know that not everyone has the same fitness goals.
The more advanced products we tested, like the Charge 2 and Ionic, offer more than just your basic step counting features and venture into the realm of integrating with your daily life (you can receive text and call notifications, track your heart rate and sleep patterns, among other things) — plus, you can even store music and make payments on the Ionic. You can view your progress with both models via the mobile app, which can sync your isolated workout data into one digestible report (cardio, heart rate, distance traveled, etc). But if you don’t want all those bells and whistles and are just looking for some basic stats, the Flex 2 might be more your style. It keeps track of your daily steps and calories, but doesn’t offer a heart rate tracker, guided breathing sessions, or sleep tracking like the more advanced models.
From our testing experience with finding the best fitness tracker and from research in the Fitbit Community forum, we expected some Fitbits to perform better than others for certain metrics. We wanted to find which Fitbits were the most accurate in all three categories used to calculate your fitness achievements: steps, distance, and heart rate. Most forum users estimated that data can be off by up to 10% (though the margin of error varies by model).
We valued Fitbits that stood out in most categories, because a small discrepancy in heart rate may not matter if your Fitbit is nearly perfect at measuring distance and steps — but when multiple figures are off, it’s hard to know if you’ve really burned 100 calories or just 50. No Fitbit was right 100% of the time , but some got closer than others or were off by the same amount every time (consider the usefulness of a clock that’s consistently 10 minutes fast compared to one that’s sometimes five minutes fast and other times five minutes slow).
We counted out 300 steps while wearing a heart rate chest strap — these track the electrical signal emitted as your heart contracts and are much more accurate than wrist wearables. We used the app for our chest strap to keep track of how far we ran, then we looked at our Fitbit stats.
Fitbits typically use two methods to scroll through different screens: clicking and tapping. We gave points to models that were straightforward and accessible, and dinged those that we had to fight with simply to see our daily stats. Testers unanimously preferred the ability to click rather than being forced to tap. The Zip, Alta, and Alta HR operate by tapping through each screen to view time, steps, distance, and calories burned. The Fitbit Charge 2 offers a hybrid input with a side button to click through the main pages, but you need to tap to scroll through extra options on each page. It’s fairly responsive, though it does miss a few beats. The smartwatches take things to the next level with a responsive touchscreen. With larger screens, the Blaze and Fitbit Ionic are visually appealing and extremely intuitive while offering more icons and pages.
We asked testers whether each Fitbit was comfortable and if they’d consider wearing it all day (and night) long. This is where personal preference started to show. Fitbit makes bands in two different styles. Most use a standard watch-style band with a small buckle, but both the Flex 2 and the Alta come standard with a two-pronged hole-punch band instead.
Testers universally agreed that the hole-punch bands were uncomfortable and difficult to put on properly. Several testers found that the prongs were too loose and the Fitbit would fall off their arm unexpectedly. On the other hand, some found the prongs couldn’t fully insert into the band without jabbing into their wrist. Testers did, however, prefer the extra leather bands that we ordered for the Ionic and the Alta (available for every model), which were more comfortable and less conspicuous. That said, they’re not great if you’re getting sweaty at the gym. Getting a new band, in whatever material, is also an easy way to mix up your style with a new color, or sidestep the two-prong fastener problem for the Flex 2.
The 3 Best Fitbits
Why we chose it
Impressive, easy-to-use functions
The Charge 2 has just enough features to track all your fitness goals without being overwhelming. It records steps, calories burned, distance, heart rate, and offers activity tracking. It’s easy to click through to see your daily steps, calories, and current heart rate, as well as activate a run exercise, use the stopwatch, start Fitbit’s guided relaxation exercise, or even check your vitals. Many of our testers commented that the Charge 2’s button to cycle through the display options was also much more reliable than the tap method of the similar Alta and Alta HR.
When you start up an exercise routine, the Charge 2 will isolate the data and sync it to your Fitbit app so you can see how effective your workout was outside of your daily statistics. There’s also a responsive tap mechanism to switch between activity types, so you can label your exercise as Run, Weights, Treadmill, Workout, Elliptical, Bike, or Intervals. It even reminds you throughout the day to move, sending you alerts encouraging you to take 250 steps per hour.
Integrates with daily life
With a small buzz, you’ll be able to see any texts or phone calls on the Charge 2’s screen and can decide whether to stop your workout for an important message, or leave your phone in your gym bag. If you’d prefer your gym time (or any other time) to be strictly offline, it’s easy to disable notifications, too.
Tracks miles accurately
The Charge 2 was highly accurate at estimating how many miles we traveled, although it gave us a few extra steps (an average of 4% more) for every hundred steps we actually took. It’s not perfect, but it’s also unlikely to disrupt your daily fitness goals.
Comfortable, sleek style
Additionally, the Charge 2 comes with a watch-style band that’s comfortable and easy to adjust. Our testers initially thought that the Charge 2’s default silicone-like band would be uncomfortable or pull on arm hair, as it did with the Altas, whose slim bands move more often across the wrist. However, while the Charge 2 is made of the same material, its broader band reduces this movement resulting in a better fit. Replacement bands are also available through both Fitbit and Amazon.
Points to consider
Heart rate accuracy
The Charge 2 consistently underestimated our heart rate (both average and maximum) by about 10%. This can lead to misleading results, especially when it comes to accuracy in calories burned during your workout. We aren’t the only ones critical of this feature: A study published in PLOS ONE also found the Charge 2 underestimated heart rate. While ballpark heart rates may be fine for lowkey everyday use or general exercise, if you want to get serious about your stats you may be better off with a more accurate chest strap wearable.
There are also concerns about the Charge 2 band’s insecurity. After a year of use, the band tends to pop off the body of the Fitbit, making it increasingly difficult to wear during workouts. Some of our testers experienced this, and the Fitbit Community forum contains similar complaints. In some cases, Fitbit may send you a replacement band, but keep in mind you’ll probably be on the hook to buy a new band at some point.
Most of our testers liked having the broader screen of the Charge 2 compared to the Altas. It fits more information on the screen at a glance, and because it’s broader, it lies more evenly on the wrist. However, if you’re looking for something less conspicuous and don’t need a screen, consider the Flex 2 for half the price.
Why we chose it
The Flex 2 has many of the same functions as the Charge 2, it just communicates with a series of lights instead of a screen. Both have reminders to move (hourly check-ins to make sure you get in Fitbit’s recommended 250 steps per hour), track steps and miles, and notify you of texts and calls. Plus, the Flex 2 is swim proof for up to 100 m deep.
Except for its small, color-coded lights, the Flex 2 isn’t flashy, which is great if you want a fitness tracker that doesn’t look like a fitness tracker. The device itself, which pops into a silicone band, is tiny — smaller than a AAA battery. This makes it one of the easiest to customize, as both Fitbit and Amazon offer a variety of bands, jewelry-styled bangles, or necklaces for your Flex 2.
Points to consider
No heart rate tracker
The biggest drawback is that the Flex 2 doesn’t have a heart rate tracker, and while it was more accurate than some devices (the Alta HR, the Blaze, and the Alta) for steps and miles, it’s not in the overall top five for accuracy, either. It underestimated steps by up to 13% (potentially robbing you of more than 1 of every 10 steps) and inconsistently over- and underestimated our miles by a similar margin. While we weren’t fans of this disparity, the Flex 2 is the only low-profile, budget Fitbit that has almost all of the features of its larger siblings. For more accuracy, you can opt for fewer features — like the Zip, a dedicated step-counter — or upgrade to either the Charge 2 or the Ionic, both of which offered better, although still not perfect, accuracy.
We fought to put on the Flex 2 and, once on, also struggled to take it off, which made finding the right fit a challenge. One tester with sensitive skin ended up with a small rash where the Flex 2 rubbed against her skin as she pried it loose. Testers universally preferred the buckle clasp of the watch-style bands: They were easy to put on, take off, and adjust. If you go with the Flex 2, consider upgrading the band as a priority.
Why we chose it
The Ionic has all of the features of the Charge 2 and then some. As a smartwatch, the Ionic comes with a few bonus features: You’ll be able to store music directly on it and stream straight to a pair of bluetooth headphones, so you don’t need to carry your phone with you on your morning walk. It has a high-definition color touchscreen that’s really responsive, as are three navigation buttons. Plus, you can make payments with it, if you feel like leaving your wallet at home.
Step and distance accuracy
The Ionic is remarkably accurate. This smartwatch almost perfectly counted our steps, off by less than 1% (only one step was miscounted for every 200). It tracked distance with near-similar precision (98%); only the Charge 2 beat it for accuracy in this arena (99%).
Bonus workout features
You can use your Fitbit Ionic watch to guide you through a series of preset workouts via Fitbit Coach. The app gives you a preview of the workout on your watch so you can observe how to complete each move properly, and your watch will vibrate when it’s time to start and stop. We liked this interactivity and this feature is great for those looking for extra guidance for their workouts. The Fitbit Coach subscription costs $40 per year and has flexible customization options so you can choose which workouts to store on your watch.
Points to consider
Heart rate accuracy
The Ionic struggled a bit with measuring heart rate, underestimating average heart rates by up to 14 bpm and misreading maximum heart rate by up to 12 bpm. The comparable smartwatch at the time of testing was the Blaze, which did a little better with average heart rate, only underestimating by up to 10 bpm, but varied more wildly when it came to maximum heart rate results. (Hopefully, Fitbit’s latest foray into smartwatch territory, the Versa, will do a better job and record more accurate results. Stay tuned for upcoming testing.)
Uncomfortable rubber wristband
Our testers had mixed feelings about the comfort of the Ionic. They universally preferred the extra accessory leather band (purchased separately) over the silicone-like band that comes standard. The soft leather helped the Ionic blend in as a watch more than the sporty-like rubber wristband did. This doesn’t bode well for exercising, though, as you might not want to get your sweat on while wearing a leather band.
Guide to Fitbits
How to find the best Fitbit for you
Think about your exercise preferences
If you like tracking your exercise metrics and seeing concrete numbers after a long run or hot yoga session, then you’ll probably enjoy using a more in-depth fitness tracker (like the Charge 2 or Ionic) to keep up with your fitness journey. For those of you who gauge fitness success by how you feel, having access to numbers on your progress at all times might be overwhelming — you could try a tracker that goes less in-depth, like the Flex 2. It’s important to note that fitness trackers can help improve heart health by showing you how much activity you’re actually fitting into your day, which can help you make decisions on whether, and how, to adjust your existing routine.
Consider what functions you want
If you get enough screen time and use exercise as a way to escape the omnipresent grip of your smartphone, tablet, or computer — a tracker with basic functionality (step counting, distance tracking), like the Flex 2, might be your best bet. But if you want a way to track your heart rate, floors climbed, control music, make payments, and even read a few messages all while hiking up a step climber, then you’ll probably want to consider a smartwatch, like the Ionic.
If you’re down to two or three of your favorite Fitbit products and can’t make a decision, Fitbit has a comparison tool that lays it all out for you. Think about what matters to you most — whether it be sleep tracking, receiving smartphone notifications, guided breathing sessions, or simply counting steps — and see how your own top picks stack up.
Know Fitbit accuracy will vary
Even if Fitbit measured all of its promised data accurately, there are a lot of variables that go into how your particular body consumes, uses, and stores energy that affect calorie tracking, for example. Fitbit currently doesn’t calculate or adjust for individual metabolisms.
Although no Fitbit is going to be completely accurate all of the time, the company does have a slew of resources to help you understand the science behind its products. Wrist-based devices leave more room for error when it comes to step count because they also have to account for arm movements, whereas a device that clips to your torso might get you a more accurate number. Looser wrist devices will also vary your data — they might miss a few steps or heartbeats. We suggest learning the best ways to manage, wear, and use your product in order to yield the most accurate results.
Get familiar with the app
We love the Fitbit app. When you first open it up, you’ll be directed to the Dashboard, which has all of your statistics for the day so far. As you get closer to your personal daily goal, the blue track meter fills up. Clicking on any of these small icons (steps, floors, miles, cals, and minutes) will show how often this week you’ve completed each goal and how that compares to your past data.
Clicking on the Sleep Tracking icon brings you to a detailed analysis of how you slept the previous night. You’ll be able to see how often, how long, and when you were awake, in REM, light, and deep sleep, and track your patterns over time (as well as how these compare to averages for your demographic).
There are also weight, water, and food icons, where you can input what you’ve had to eat or drink so far today, as well as track your weight. If you purchase Fitbit’s Aria 2 scale, it’ll sync your weight data automatically. The Food Tracker lets you scan a barcode or manually enter what you ate for lunch. You get a summary of calories consumed alongside a break down of nutrients into carbohydrates, fats, and protein.
Join the Fitbit community
We tend to feed off of other people’s behaviors, especially when it comes to exercise and leading a healthy lifestyle. The community is one of the best things about Fitbit. In addition to being able to link to your friends, you can connect to various groups based on shared interests. Once in a group, you can see recent posts people have made about their own fitness journeys, ask questions, receive tips, and chime in with your own advice and encouragements.
What does a Fitbit do?
A Fitbit is essentially a fitness tracker that monitors your health — from exercise and weight to your diet and sleeping habits. But it does more than crunch the numbers on your fitness progress; you can sync your statistics to your phone and set goals for yourself. You’re also not an island in your fitness journey with these products, either. Fitbit places great emphasis on community and even lets you start challenges with friends and family to reach certain goals.
How does Fitbit track heart rate?
Fitbit’s “PurePulse” technology uses the LED lights on your Fitbit to reflect back onto the skin and scan for changes in blood volume. Apple uses a similar technology (photoplethysmography) for its smartwatches, using LED lights to detect changes in blood flow. As your heart beats, more or less light will be absorbed depending on whether your heart is expanding or contracting. By flashing green lights at your skin, Fitbit tracks when less light is absorbed than usual and estimates your heart rate from that.
How do I get the most accurate data from my Fitbit product?
You can always adjust your settings, so if you feel your Fitbit isn’t giving you accurate data, start with the basics — like making sure your height and weight are entered accurately. Then, check and see if you’re wearing your device the right way.
What is the best way to wear a Fitbit?
This will largely depend on the product — you obviously won’t wear a clip-on the same way you would a wristband or necklace. For most of the day, it’s best to make sure you can fit two or three fingers between your Fitbit and your wrist to ensure a comfortable fit. But during exercise, you’ll want to wear it snugly against your wrist in order to get more accurate heart rate tracking.
The Best Fitbits: Summed Up
approx. +4% (extra 4 steps for every 100)
approx. -1% to -13% (minus 1-13 steps for every 100)
92% accurate (inconsistently +/-)
97.6% accurate (approx. -2.4%)
|Heart rate avg.||
approx. -10% (-5 to -10 bpm)
approx. -10% (-6 to -14 bpm)
|Heart rate max||
approx. -8% (-11 to -19 bpm)
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