However, just because there's a new band on the block, that doesn't mean the Charge 2 is no longer available to buy – or that it's not still a mightily impressive bit of kit. While its successor has a raft of new features and brings a refined design, it may not be the right tracker for you.
Read this: Which Fitbit should you buy?
In order to help you out in your choice between the two Charge devices, we've been living with the two to see how they compare. Read on below for all the details regarding design, features and that all-important price.
Fitbit Charge 3 v Charge 2: Design
Fitbit Charge 3: 18.325mm wide, available in small and large sizes
Fitbit Charge 2: 21.45mm wide, available in small, large and extra-large sizes
We've put these two trackers side-by-side and there are definitely some design changes that make the Charge 3 a more desirable option to wear 24/7. It has a slightly bigger (and brighter) touchscreen OLED display, a slimmer casing that sits more naturally and comfortably on the wrist, and a much wider range of bands and finishes. So, you can dress it up to make it feel less like a fitness tracker. Another big difference is that the newer Charge is waterproof. The Charge 2 isn't, and that means the Charge 3 is fit for swimming in the pool or in the ocean at a water depth of up to 50 metres.
That's not to say the Charge 2 isn't still a decent-looking tracker. It also has one thing that the Charge 3 doesn't, and that's a solitary physical button to turn on the device and skip back through menus. Fitbit has introduced a new inductive button that lies either side of the screen and serves the same purpose on the newer Charge. Removing the physical button meant Fitbit could make its new wearable waterproof, so it looks like a good compromise.
(Above: Fitbit Charge 2)
Both Charge devices are equipped with Fitbit's PurePulse heart rate sensor for measuring workout intensity and offering resting heart rate readings, but if you want that new SpO2 sensor, the Charge 3 is the one you need. The sensor has already been included in Fitbit's two smartwatches, and is designed to be used for monitoring serious health issues. But it's not really being put to use right now, so you wouldn't be missing out massively by not having it just yet.
If GPS is a desirable feature, then you're out of luck with both of these trackers. You'll still need to rely on your phone's GPS to map routes for runs and rides. Currently, the Fitbit Ionic smartwatch and the long-retired Fitbit Surge are the only wearables in the Fitbit family that have this feature built in.
Fitbit Charge 3 v Charge 2: Activity tracking features
Fitbit Charge 3: 24/7 activity tracking, swim tracking, goal-based workouts, SmartTrack
Fitbit Charge 2: 24/7 activity tracking, workout modes, SmartTrack
The core fitness tracker features across the two devices are largely the same. Given that Fitbit can offer new features through software updates, we wouldn't be surprised if it'll at least try do the same for the Charge 2. It's also worth mentioning that features like advanced sleep tracking and female health tracking are available to all Fitbit trackers via the companion app. You just might see a bit more of that data on the Charge 3 itself than you can on the Charge 2.
Both will count your steps (including stairs climbed), log sleep and offer reminders to move. On the mindfulness front you're covered too, with guided breathing features to help you de-stress during the day.
Fitbit's SmartTrack tech will automatically recognise a range of exercises and that tech does now extend to swimming on the Charge 3, thanks to its waterproof design. So if you care about swimming, the new Charge is the one you want.
There are multi-sports tracking modes for the likes of running and cycling. One small addition you'll find on the Charge 3 that the Charge 2 lacks is the new goal-based feature. This lets you set a target distance or time to work towards during a workout. It's not groundbreaking, but for anyone looking for that extra motivational push, it may well have appeal.
Fitbit Charge 3 v Charge 2: Smart features
Fitbit Charge 3: First and third party notification support, quick replies, Fitbit Pay (special edition only)
Fitbit Charge 2: Limited notification support
Fitbit has been introducing smartwatch-style features to its fitness trackers for a while now. But now that it's playing in the smartwatch space, it's working to bring more of those more advanced smarts to other members of its wearable family. While the Charge 2 does a fairly decent impression of a smartwatch, there's a whole lot more going on in this department for the Charge 3 and Fitbit has plans to add more smart skills to the latest Charge too.
Read this: The ultimate guide to the Fitbit app
In the notification support department, the Charge 2 is restricted to letting users view call, text and calendar alerts on the device. The Charge 3 will let you see alerts from all of your apps and offers the ability to send quick replies to notifications (Android phones only, unfortunately).
The Charge 3 does also offer some app support, although not to the extent of the Versa and Ionic smartwatches. You can pick between seven monochrome watch faces, and the special edition Charge 3 includes NFC so you can use Fitbit Pay to make contactless payments from the wrist.
Fitbit Charge 3 v Charge 2: Battery life and price
Fitbit Charge 3: Up to seven days battery life
Fitbit Charge 2: Up to five days battery life
The good news is that both Charges have the battery power on board to get through five day's worth of tracking. But if you want a full week, then the Charge 3 should get you those extra couple of days. Staying power does, of course, depend on the features you plan to use on a regular basis. Disabling all-day heart rate monitoring and turning off that notification support are the kind of things that can improve battery life. Based on our experience, we're sure the Charge 2 could stretch to another a day or two, but it looks like the Charge 3 will give you more.
So, let's talk price. The Charge 3 is priced at , while the Charge 2 costs roughly , depending where you buy from. The special edition Charge 3, meanwhile, will set you back .
It's also important to note that although Fitbit no longer lists the Charge 2 on its own website, you can naturally still pick it up from retailers such as Amazon. Just make sure you're scouting around, since there are now serious potential savings to be had.
Fitbit Charge 3 v Charge 2: Verdict
On paper, there are plenty of reasons here to make the upgrade from the Charge 2 to the Charge 3. It's slimmer and waterproof, has vastly improved smart features and better battery life. If you can find the Charge 2 for significantly less elsewhere, that's still a decent option – particularly if you're not too fussed about wearing it in the water, or about those health tracking possibilities that the Charge 3 has the potential to unlock in the future. But if you have a bit more money to spend, the Charge 3 is clearly the one you should be going for.