Flex 2 vs Vivosmart 3 – An Unlikely Comparison

So at the moment I’m walking around with two fitness devices on my wrist. Why? Because having just bought a Garmin Vivosmart 3 it seemed like a good opportunity to compare it with the Fitbit Flex 2 I’ve been using for the last year or more.

Now these aren’t devices that usually get rated against each other but my primary criteria puts them both in the same category; they monitor steps and sleep, have a silent alarm, receive call and text notifications, are waterproof and importantly both are small enough not to be bulky on a small wrist (and are moderately priced).
The Garmin also provides a screen and some more sensors which I’ll mention later.

The Basics

Fitbit Flex 2 and Garmin Vivosmart 3

Size wise they’re both very similar, the Garmin is wider at 19mm compared to the Fitbit’s 12mm but both look like a plain black wristband. The Garmin hides a screen whereas the Fitbit makes do with a line of five LEDs. Both require a tap or two to wake their display.
Both are waterproof enough to go swimming in, or in my case, to be showered in sleepily at 6am.

Battery life is similar, both claim about five days, so charging twice a week is probably necessary. Both come with their own proprietary USB charging cable. The Fitbit device is detachable from the wristband so simply pops into the cradle, the Garmin requires lining up some pins and squeezing the crocodile clip to hold it in place. Once you plug it in, the screen does give you an indication that it is charging and as it is easy to misalign the device you need to watch to be sure that it is.

As with everything these days both come with an app that runs on your phone (in my case Android) and syncs with it. They’re very different in style but both give you access to all the information the tracker is collecting.
Again both offer a manual sync function and will sync automatically sometimes too. The Garmin has never failed to sync on command while the Fitbit often requires several attempts before it will sync with its application.
Fitbit does offer some integration with IFTTT which the Garmin doesn’t which is a shame.


Both devices seem to track my steps similarly within a few hundred steps, varying as to which one counts higher. The Garmin’s screen means you can watch the steps counting up on your wrist while the Fitbit displays a green LED and uses the other four to show the fraction of your goal you’ve reached.
Both apps allow you to set your own daily goal if you wish but while Fitbit defaults to offering you ten thousand steps, Garmin will optionally change your goal every day based on your recent performance to encourage you to improve (their slogan is ‘beat yesterday’).


The Fitbit (left) thinks I’ve been much more ‘active’ than the Garmin.

Both devices agree that you should be aiming for one hundred and fifty minutes per week of moderate exercise in at least ten minute bursts. Fitbit calls these active minutes and walking briskly around town is enough to get me some.
The Garmin calls these intensity minutes and tracks them apparently using step rate and heart rate. It will give you double value for vigorous activity (if your heart rate gets sufficiently high). In practice the Garmin often doesn’t register any minutes at all even when my walk was enough to leave me tired. I suspect it is insisting more strictly on the ‘continuous ten minutes’ so that pausing to cross the road is enough to stop it counting.


Both devices offer sleep tracking. In general they agree about the time I went to bed and got up. The Garmin insists on knowing my expected sleep pattern and doesn’t seem to track sleep much outside that time (missing afternoon naps). In both cases the times can be edited when I know they got it wrong. But while the Fitbit is happy to track multiple sleeps the Garmin insists on only one sleep record a day.


Again both have a silent alarm which you set from the application. They both have a snooze feature and both allow you to set more than one alarm and allow each alarm to recur on the days you choose. The Garmin seems to send  a new alarm to the device more reliably than the Fitbit (again this is linked to the unreliable syncing). The Garmin vibration seems weaker than the Fitbit but is sufficient to wake me normally.


Both devices offer call and text notifications. While the Fitbit is limited to flashing the LEDs in a ‘call’ or a ‘text’ pattern the Garmin can show me who is calling (and let me answer the call) or even the content of text messages with a little tapping and swiping. The Garmin will also show other applications notifications too and you can select which applications it will display notifications for.

Garmin Extras

The Garmin comes with a few more tricks up its (or your) sleeve, so to speak. Firstly the display includes a time screen which means it can function as an actual watch. Lifting your arm to look at it is enough to wake the display (as long as you over-emphasise the motion slightly).

It also measures floors climbed (and indeed descended). You can set a goal for floors climbed too. The climbing algorithm is a little unreliable, leading to several trips up and down the staircase to get that last one flight before the goal; but equally a lunchtime walk up a small hill left it convinced I’d climbed thirty flights of stairs!

It also has a heart rate sensor, which is used to track exercise, fitness and stress. While the heart rate itself is interesting, I’m not entirely convinced of the accuracy of how it uses that data.

The display can be configured to show a selection of widgets, swiping between them. The basics (time, steps, stairs etc) are all here plus phone linked ones such as notifications, music control and weather. Beware of the units you choose though; if, like me, you want to measure your distance in miles then you will have to have your temperatures displayed in Farenheit.

The Applications

Both devices link to an Android app and a web-based dashboard. The Garmin dashboard is almost too complicated but is also incredibly flexible. Some measurements (e.g. VO2 Max) are hidden in the application menu although easier to find in the dashboard. The Fitbit app is cleaner and simpler although the way it scrolls through daily data in the same screen as some of  today’s can be a little confusing. On the whole though they both display the basics perfectly well once you get used to them.

The applications allow you to access some additional features. Both allow you to track your weight, but while Garmin offers me pounds or kilograms the Fitbit will also allow me to log my weight in stones (although it randomly sets itself back to kilograms every now and then). The Fitbit also allows you to log body fat percentage, calories consumed and water drunk making it much better as a weight management (rather than a fitness) tool.

The Fitbit application also allows you to log your walks or runs using the phones GPS and your step count. Indeed if you don’t have a Fitbit device at all the application will actually allow you to use your phone as the device.

The result? Well I’m pretty happy with the Garmin in general but I don’t think I’ll be focusing on active minutes any more as they’re just too hard to get reliably and I’ll keep the Fitbit application around for now.

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