Fitbit offers numerous devices in the activity tracking market, from the plain and simple Flex 2 to its GPS sportswatch, known to friends as Ionic.

The latest device to join the Fitbit family is the Charge 3. We've compared it to the Fitbit Charge 2, as well as the Charge and Charge HR to see how the devices differ and help you work out whether or not you should upgrade.

  • Charge HR: Small OLED display, buckle fastening, PurePulse HR monitor, plastic, non-removable straps
  • Charge 2: Large OLED tap display, buckle, PurePulse HR monitor, stainless steel, interchangeable straps
  • Charge 3: Large OLED touchscreen display, buckle, PurePulse HR, SPO2 monitor, aluminium, interchangeable straps, water resistant

The Fitbit Charge and Charge HR both measure 21mm wide and they both have a small OLED display and a non-removable textured, elastomer band. There is a small button on the left-hand side of the display and they are both water resistant up to 1ATM but neither are swim proof.

The strap is fastened with a stainless steel clasp on the Charge HR and two pins on the Charge. The Charge HR also features Fitbit's PurePulse Heart Rate monitor on its underside, but the Charge doesn't.

The Charge 2 offers a similar strap and clasp to the Charge HR, made from the same flexible elastomer material with a stainless steel buckle and measuring 21mm in width. The strap on the Charge 2 is interchangeable however, featuring a clip mechanism, like the Fitbit Alta HR, allowing users to switch between the various bands sold separately by Fitbit.

The display is much larger on the Charge 2 compared to the Charge HR, five times larger in fact, taking over the majority of the top of the device. There is also a larger button on the left of the display and a stainless steel body underneath.

The PurePulse Heart Rate Monitor is featured on the underside of the Charge 2 like the Charge HR, and there are four colour options, with two Special Edition options. The Charge 2 is sweat, rain and splash proof like its predecessors, but not swim-proof.

The Charge 3 refines the Charge 2's design, offering a smoother, sleeker finish with an elastomer band that has a diamond-etched pattern and a buckle fastening. The Charge 3's casing is aluminium rather than stainless steel, making it 20 per cent lighter than the Charge 2 and it features a more refined mechanism for changing the straps too.

Like the Charge 2, the PurePulse heart rate monitor is on the underside of the Charge 3, though it is coupled with a SPO2 monitor on the new device. The Charge 3 also has a 40 per cent larger display than the Charge 2 and it is a touchscreen now rather than just tap, protected by Corning Gorilla Glass.

Perhaps most importantly however, the button on the left of the Charge 3 is an inductive button rather than a physical button, allowing for the Charge 3 to be water resistance up to 50-metres and swim-proof.

  • Charge HR: Activity monitoring, sleep tracking, auto exercise recognition, HR monitoring, call notifications
  • Charge 2: Adds sleep stages, multi-sport tracking, connected GPS, cardio fitness level, guided breather, text and calendar alerts
  • Charge 3: Adds swim tracking, goal-based exercise, run detect with auto stop, accept/reject calls, quick replies, NFC (Special Edition) 

Both the Charge and Charge HR track steps, distance, calories burned, floors climbed, active minutes, hourly activity and stationary time. They also both allow the user to see daily stats and the time on the small display, along with incoming call notifications.

The Charge and Charge HR are capable of sleep monitoring and they both feature silent alarms. Additionally, they both have SmartTrack on board, which automatically recognises when you exercise and records it in the app.

The Charge HR differs slightly from the Charge in that it has the PurePulse Heart Rate monitor on board, as we mentioned. This gives users an automatic and continuous heart rate reading from their wrist.

The Charge 2 features all-day activity and sleep monitoring, meaning all the same features as the Charge and Charge HR, though its sleep tracking is more advanced thanks to sleep stages. It also offers Multi-Sport tracking, continuous heart rate monitoring and the Charge 2 will deliver smartphone notifications in the form of calendar alerts, text messages and call notifications too.

Additionally, the Charge 2 features Connected GPS, a feature called Cardio Fitness Level that allows users to see a personalised Cardio score and another feature called Guided Breathing. This latter feature offers personalised breathing sessions based on your heart rate.

The Charge 3 unsurprisingly offers all the features found on the Charge 2, as well as a few extras. Thanks to the water resistance, the Charge 3 has swim tracking on board, but it also has a new feature called Goal-Based Exercise, allowing you to personalise more than 15 exercise mode with a specific calories burned, duration or distance goal. There is Run Detect with auto stop on the Charge 3 too, as well as a timer option and weather information.

You'll also be able to accept or reject calls on the Charge 3, as well as send Quick Replies if you are an Android user. Special Edition models of the Charge 3 have an NFC chip inside too, meaning they are Fitbit Pay enabled.

  • Charge 3 cheaper than Charge 2 

The Fitbit Charge and Charge HR are no longer available to buy directly through Fitbit but you might be considering upgrading from them, which is why they are included in this feature.

The Charge 2 costs £139.99 and although the Special Edition models were originally £20 more expensive, they now cost the same.

The Charge 3 will start at £129.99, with the Special Edition Charge 3 models costing £149.99.