Models now track floors climbed, calories burned, sleep patterns and come in multiple colors.
Some advanced models, like theVersa, combine tracker and smartwatch abilities.
Read on to know more about each.
Their battery lives are also similar they can go uncharged for about 7 days.
Both also have a mindfulness app configured with deep breathing exercises.
However, the main difference between the two is that the Charge 4 has a built-in GPS.
The Charge 3 tracks movement as a Bluetooth-Enabled unit and you would need your phone with you.
The Charge 4 also lets you control your Spotify playlist while working out, unlike the Charge 3.
Considering that both are priced similarly, Tech Radar recommends the Charge 4 over the Charge 3.
