Fitbit Flex 2 review

The original Fitbit Flex has been around since 2013. It is a simple, reasonably small fitness tracker, not terribly expensive and not jam-packed with features. 

The Fitbit Flex 2, which arrived in late 2016, keeps that style, while adding more customization and full swim-ready water resistance (a first for Fitbit), all crammed into a smaller band.

But not everything has been improved, with battery life proving a particular disappointment, and in the three years since the original Fitbit Flex a number of rivals have emerged - including some from Fitbit itself, so is the Fitbit Flex 2 enough of an update? 

Fitbit Flex 2 price and release date

Although Fitbit has pushed some major upgrades into the Flex 2, it's around the same price as its predecessor too with a launch price of $99.95 (£79.99, AU$149.95).

Since it launched back in 2016, we've seen the price of the Fitbit Flex 2 drop down to $59.95/£54.99 in the US and UK. Those in Australia are still seeing prices of around AU$149.95.

That's a significant discount right there making it a much more affordable option than when the Flex 2 launched, but we may also see some further price cuts and deals as the Flex 2 ages.

Design

• Slim, slight and comfortable
• A wide range of colors and straps are available

The Fitbit Flex 2 is a skinny, slight, water resistant fitness tracker, small enough that you can wear a watch alongside it without looking like you’re wearing two timepieces.

Its band is about a centimeter wide, and the width is more-or-less the same across the whole tracker. As Fitbit says, it’s about 30% smaller than the last Fitbit Flex.

The make-up of the Fitbit Flex 2 is the same as before, though. Its brain is a little nugget of plastic that fits into the rubber strap, and can be popped out to charge.

The main benefit of this style is that you can replace the band, and get versions that look a lot jazzier than the black rubbery one Fitbit sent us. Buy direct from Fitbit and you can pick from four colors: black, lavender, magenta and navy blue. Fitbit offers packs of other strap colors too.

These rubbery straps have a low-key diagonal embossed pattern. If you’re after something a little more ostentatious, you can also get jewelry-like metal ‘bangles’, and pendants that turn the Flex 2 into a necklace.

As these are made of higher-end materials they add a lot to the cost. The silver bangle is made of stainless steel and costs $89.95, £69.99, AU$149.95, the gold and pink ones are gold-plated steel and cost $99.95, £79.99, AU$169.95.

You double the cost of the Flex 2 by buying one of these, but in return you get a tracker that looks like a piece of jewelry.

Back to the rubbery one we actually have, the Fitbit Flex 2 uses the same style of button clasp as the old Flex. This has been a bit of a sore point for some Flex owners in the past, as it can be hard to seal, making you push with all your might against your wrist: not comfy.

However, Fitbit does seem to have improved this, as we haven’t found it too hard to close the thing, although a decent push is still needed.

The standard Fitbit Flex 2 comes with two sizes of strap, they’re the same width but there’s a longer one for people with chunkier wrists.

Make sure the strap isn’t too tight and the Flex 2 becomes a fitness tracker you’ll completely forget you’re wearing. Keeping it on at night is no hardship at all: an important win for a low-key tracker like this.

• Very basic tracking skills
• Auto-recognition of different exercises
• No screen, just LEDs

Let’s deal with what the Flex actually does apart from sitting on your wrist. There are five little LEDs on the brain of the Flex 2, that tell you how close you are to your daily steps goal, and light up when you get certain notifications.

One of them is a color LED that changes depending on the message relayed. Reminders to move are purple, calls fire up yellow and it’s blue for WhatsApp or SMS messages.

One of the Flex 2’s issues is that it doesn’t make this clear anywhere apart from the in-app Flex 2 guide that few people will read.

The other main feature is a vibration motor that buzzes when you get these notifications, or to wake you up using the Silent Alarm feature.

In the Fitbit app, you can set a time to be woken up with a nagging buzz on your wrist. It takes a bit of getting used to, but is a bit less offensive than some of your phone’s inbuilt tones.

What the Fitbit Flex 2 lacks are any extra bits of fitness hardware. There’s no heart rate sensor and no GPS, so if you want those you’ll have to buy one of Fitbit’s more expensive wearables. The Fitbit Ionic and the Fitbit Surge for example has both GPS and heart rate tracking, but both come at a much higher cost.

There’s not even any kind of clock on the Flex 2, or an altimeter to count how many flights of stairs you tackle. It’s a minimal tracker.

This means it’s only really useful as a light way to check up on roughly how many steps you take each day, a reminder to get off your posterior more.

It tallies calories and distance as well, but we’d advise not looking too hard at these figures. While the Fitbit Flex 2 has a clever-enough algorithm to discount any arm movements you make while at your desk (this may depend on how much you wave a fist at your laptop/monitor), no wrist-worn tracker is that accurate. Take them as loose measurements.

The Flex 2 can also remind you to move each hour if you haven’t taken at least 250 steps. It can be annoying, but is a good idea if your goal is to become a bit more active.

Fitbit has a go at using software to appeal to the more active among you, with auto-recognition of different kinds of exercise.

When you run, or use the elliptical machine at the gym for 15 minutes or more, the Flex 2 will monitor the cadence or your movements to auto-add these kinds of exercise to your daily activities as separate entries.

The only exception to this auto-recognition is swim tracking, which you need to manually switch on, as it apparently has an impact on battery life and is switched off as standard.

That aside, the Flex 2 is a handy way to tally-up your gym sessions and jogs without doing so manually. It also separates out longer walks.  

This is one of the best bits of the Fitbit software, making what are effectively quite simple measurements of your arm movements seem a whole lot richer. You can find exactly how long it took you to walk to the train station on the way to work, for example.

The app

• Packed full of challenges and achievements
• Makes fitness fun
• Lacks statistical depth

The useful auto-tracking described above is all thanks to Fitbit’s app, which has benefited from years of development tweaks at this point. It’s a great little app that’s a pleasure to jump into several times a day, putting all the data you want to see in front of your eyeballs.

There’s nothing like the statistical depth of the Garmin Connect system, which is geared towards improving your performance and letting you see, for example, the variation of pace in your 10km runs. But Fitbit’s app has another kind of depth, one based on motivation.

The Fitbit app is packed with challenges and achievements, similar to the sort of techniques free-to-play games use to keep you hooked. You can challenge other Fitbit-owning friends to face-offs, and there are ‘single player’ Adventures that map your steps onto a (probably) far more exciting trek.

One is the Vernal Falls hike in Yosemite national park. The aim is to walk 15,000 steps in one day between 6am and 10pm. As you rack up steps, you can see how far you’ve made it in the satellite map, and unlock ‘journal’ entries relating to the real-life walk.

In reality you might just be walking around town or your local park, but as with other parts of the Fitbit software it’s about adding a fun dimension to something quite prosaic.

Again, if you’re trying to gear up for a marathon, you’d be much better off with a budget GPS watch like the Garmin Forerunner 35 or Polar M200.

However, a Flex 2 is a good fit if you want a tracker that will give you that extra incentive to be a bit more active in a low-exertion way. It works best if you have friends who also own a Fitbit or use the Fitbit app, though.

At the end of 2017, Fitbit launched a partner to its main app, called Fitbit Coach. This paid app brings more serious fitness and coaching skills to the Fitbit network with 100s of video workout drills you can do, many of which are from the increasingly popular world of HIIT.  

Fitbit Coach can be accessed from the main app by way of a Guidance section, where you can choose a workout but you'll need to download Fitbit Coach and this will be launched when you select a workout. Nike takes this multi-app approach where there are distinct apps for strength training and running, but it's a little annoying to have download both apps and be flicked back and forth.

That gripe aside, Fitbit Coach is a serious training partner, recommending personalised video workouts based on your Fitbit activity and making it simple to follow loads of different exercises, not unlike we've seen done with Moov Now. 

There's run and walk coaching too and you can choose your preferred trainer and Fitbit Radio is there to provide musical motivation. 

There are some free workout sessions in the app these are frustratingly hard to find among all those you'll need to pay for a premium account to 

Access to the premium app will still set you back £5.99 per month for £29.99 ($39.99, about AU$50) for the year, though there are some free workout sessions in the app too. These are frustratingly hard to find in the Coach app. 

That said, this is cheaper than a gym membership and great for equipment-free home workouts.

Battery life

• Roughly four days of life
• Slow and awkward to charge

If this is your bag, there’s just one other thing to consider - the Fitbit Flex 2’s battery life is not that good for such a low-functionality tracker.

Fitbit says it’ll last five days between charges, but we only managed four when the phone notifications were switched from SMS messages to WhatsApp ones (you can switch between SMS, WhatsApp and Hangouts), which we tend to receive much more often.

It seems likely Fitbit had to use a tiny battery in order to make the module as small as it is, and that the vibrate function uses a decent amount of charge when firing off frequently.

Switch notifications off altogether and the Fitbit Flex 2 may last over a week, but if all you want is a pedometer, the price seems quite high.

Charging is not very quick either, it takes a few hours, and involves removing the Flex 2 module and plugging it into a little dock that you then attach to your phone’s charger plug. No dedicated plug is included here.

Used day-to-day, a few times we ended up only half-charging the tracker, because we simply needed to leave the house or office before it was finished.

Fitbit does send you an email when the Flex 2 is low on juice, and you can check the power level in the app too. You’re only given vague “low”, “medium” and “full” estimates, though.

If you hate the idea of having another device to charge, consider the Garmin Vivofit 4. It uses a non-rechargeable battery that lasts for up to a year, and also functions as a watch. However, it doesn’t have a vibrate function, so is no use for notifications or as an alarm clock.

Compatibility

• Compatible with a wide range of devices
• Has issues with some Android models

The Fitbit Flex 2 is compatible with iOS, Android and Windows devices. We tried it with both an iPhone 7 Plus and a Motorola Moto Z Play, and both sync’d without any initial problems.

However, it took a couple of days before any Android notifications were sent to the band, even after turning on a ‘widget’ aid meant to help matters.

There was no magic fix: they weren’t working, it was quite annoying, and then the next day they were. Go figure. Some patience may be needed to get through a few teething problems, but this is likely to vary between Android models.

Verdict

The Fitbit Flex 2 is the kind of fitness tracker you can put on and forget you’re wearing. It can survive the bath or shower and is comfortable enough to wear 24/7 without even noticing it’s there.

Its fitness tracking hardware is extremely basic, amounting to step and swim tracking - that’s it - but the Fitbit software is clever enough to weave motivating narratives out of the data to keep you interested.

There are cheaper simple trackers available, but what really holds the Flex 2 back is battery life. While far longer-lasting than an Apple Watch, we’d ideally like to see a simple tracker like this last a week rather than 4-5 days.

Who's this for?

The relatively low price and limited functionality of the Fitbit Flex 2 makes it ideal for those just dipping their toes into fitness tech, who want a little motivation and feedback, but don't need anything feature-packed.

More serious fitness-fans, or those who want more of a smartwatch, should look elsewhere though, as the Flex 2 is a basic fitness tool, and other than notification lights has no real smartwatch features at all.

Should you buy it?

The Fitbit Flex 2's battery life stops it scoring higher, and if you need a lot of juice you should consider one of the Garmin Vivofit range instead, but the four days of use you're likely to get out of the Flex 2 shouldn't be a deal-breaker, especially if you're used to daily smartphone charges.

While it's easy to think of the Flex 2 as a glorified pedometer, the waterproofing will appeal to casual swimmers, while the app and social features make it surprisingly compelling to use.

So if all you want is the motivation to get more active it's a solid choice - just don't go in expecting a wealth of sensors and data.

First reviewed November 2016

Competition

What other devices are there on sale that may persuade you away from buying a Fitbit Flex 2? Take a look at some of our top choices.

Moov Now

The Flex 2 requires a recharge around every four days so, when considering alternatives, it’s hard to ignore the six months of battery life on offer here. The Moov Now (£50 / $60 / AU$79) offers just about everything you could want from a basic tracker and is the best option right now, in our view.

It delivers excellent real-time coaching for running, cycling, swimming and to that end its more suited to boosting sports performance than general fitness tracking. Both devices have water resistance (and swim tracking by extension), while neither bother with built-in GPS or heart-rate tracking. The Moov however, has the advantage of piggybacking on your phone’s GPS. 

• Read our Moov Now review

Huawei Band 2 Pro

You can get a lot more for your money now than in 2016, when the Fitbit Flex arrived on the scene. Case in point, the $69 (£79), Huawei Band 2 Pro, which promises heart-rate tracking, GPS and even VO2 Max readings. However, perhaps it tries to do a little too much, because the HR tracking is way off and the VO2 Max is marginal. 

Battery life is impressive as it offers 21 days in normal mode (which translates into about 4 hours with GPS and HR tracking turned on). As you’d expect, step tracking is on point. The design and interface are basic, but few are pitching for extra style points at this end of the market. 

• Read our Huawei Band 2 Pro review

Garmin Vivofit 4

A year-long battery life and a color screen? Praise the wearable tech gods! The Garmin Vivofit 4 ($79.99 / £69.99 / AU$159) offers an improved, slimmer design and a decent range of basic tracking skills. You won’t get the deep dive you see in higher-end Garmin products, but there’s more than enough to keep running and walking beginners happy. 

It’s also possible to borrow GPS from your phone and connect a chest strap if you want to go further. Instead of recharging you’ll replace the coin battery… eventually. The display’s only 88 x 88 pixels but its enough to provide basic data and a watch face. 

• Read our Garmin Vivofit 4 review