​Fitbit Charge and Fitbit Charge HR: Everything you need to know

The Fitbit Charge and Charge HR are the leading lights of the fitness tracker world – and sales of the two devices have made the company the number one wearable brand.

UPDATE: If you're looking for full verdicts on each device, then skip straight to our Fitbit Charge HR review, Fitbit Surge review and Fitbit Charge review.

While the Fitbit Surge is a running watch with every day tracking, the Fitbit Charge duo are aimed at those who want to keep an eye on their daily activity and sleep. The difference between the two?

The Charge HR uses continuous heart rate monitoring while the standard Fitbit Charge just guesses it all from the movements of your arm.

Essential reading: Best budget fitness tracker

The two are very similar in terms of features to the Jawbone UP3 and Jawbone UP2, and if that's just caused further confusion, then go check out our round-up of the top fitness trackers.

Still with us? We've put together a full run down of everything you need to know about the Fitbit Charge. And don't forget to read those reviews before you buy.

Fitbit Charge: Design and display

Both new Fitbit Charge models feature a wristband made from a flexible, durable elastomer material similar to that used in many sports watches. The duo boast surgical-grade stainless steel fasteners: a buckle on the HR and a clasp on the regular Charge.

They come in three different sizes; small, large and x-large – with wrist sizes from 5.5 inches right up to 9.1 inches catered for. The Charge band is 21mm wide, the Charge HR measures 34mm.

Both devices will be available in a range of colours. The Fitbit Charge comes in black, slate, blue and burgundy and the Fitbit Charge HR's shades are black, plum, blue, tangerine and teal.

The big design difference from the Fitbit Flex is that the new Charge trackers have a small OLED display to show the time, real-time stats and incoming caller IDs.

The Fitbit Charge HR uses the same form-factor as the Fitbit Charge, but features optical heart rate tracking.

As you can see from these two product shots, the design for the new pair is pretty similar:

The Charge HR (below) is obviously a bit bulkier due to the heart rate sensor, and features a differently textured finish plus the buckle we've already mentioned:

Fitbit Charge: Hardware and sensors

There's no GPS on board either of the new Fitbit trackers, which straight away puts them behind the Microsoft Band.

However, the good news is that, like the Microsoft Band, you don't need a chest band for 24/7 heart rate monitoring with the Charge HR. That's because the optical heart rate sensor uses LEDs to detect the blood racing through your veins. Like the Fitbit Surge, it's based on the company's new PurePulse technology.

The benefits are more accurate calorie burn tracking and performance logging from nearly every conceivable sport, especially indoor cycling and gym work, which non-heart rate sensing wearables can't track.

What's more, the Fitbit Charge HR will take note of your resting heart rate every morning, and plot it on a graph. Resting heart rate is the key metric for determining your health and for quantifying the benefits of your newly improved lifestyle. Watch the number fall as you get fitter. You can check out our guide to resting heart rate for a complete picture.

It also means that you can train using heart rate peak zones – check out our guide to heart rate training to see how you can improve your training with wearable tech.

Fitbit Charge: Activity tracking and app

Both Fitbit Charge devices will track all-day activity like steps taken, distance travelled, calories burned, floors climbed and active minutes.

There's also sleep monitoring and the sleep tracking kicks in automatically, plus there's a vibration-based silent alarm on offer too.

The OLED display will give you your stats in real-time using the Exercise Mode.

The Fitbit Charge devices sync to your smartphone or tablet app using Bluetooth 4.0, or your PC or Mac using a wireless dongle.

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The app is compatible with Windows Phone, iOS and Android and the data will also sync with the info from your Fitbit Aria Wi-Fi Scale.

The Fitbit app lets you see progress, record workouts, share and compete with your friends, log your food intake and earn badges based on your activity achievements.

Both Charge bands track seven days of detailed motion data – minute by minute – and keep daily totals for the past 30 days.

Fitbit Charge: Notifications and battery life

The Fitbit Charge OLED display doesn't extend to smartwatch notifications, as per the Fitbit Surge or the Garmin Vivosmart; its primary (and only) smartphone syncing skill is caller ID for incoming calls.

The band is 1ATM water-resistant, meaning it can be used in the shower but not for swimming, which does put it at a disadvantage to the Misfit Flash when it comes to tracking time in the pool.

Battery life is stated as seven days for the Charge, five for the Charge HR and you'll get a full charge in one to two hours.

Fitbit Charge and Charge HR: Price

You can bag a Fitbit Charge [Amazon] with the non-biometric features for although in reality you should be able to find some significant discounts on that RRP.

When it comes to the Fitbit Charge HR [Amazon], you're looking at a slightly beefier but again, prices will vary and you can already find that cheaper elsewhere.

They're certainly not cheap, but for our money the Charge HR and its continuous heart rate monitoring is a decent price for the amount of insight you get.