To use it, hold your palm over the watch's face and sit quietly for a minute. One of the main differences between the two watches is the Fitbit Sense's stress measurement sensor, which measures changes in your skin's conductivity (electrodermal activity, or EDA), which can be indicative of physical or emotional stress. Fitbit Sense can also take ECG readings.

The Fitbit Sense is available in carbon/graphite and lunar white/soft gold.

The Fitbit Versa 3 comes in midnight/soft gold, black/black and pink clay/soft gold. Otherwise, the only differences are the default watch faces (which can be changed through the Fitbit app) and the choice of colors. The only noticeable difference is a small indentation on either side of the Fitbit Sense's screen, indicating where to place your hand to use the electrodermal activity sensor (more on that shortly). The Fitbit Sense and Fitbit Versa 3 look almost identical, with the same square face, aluminum case, and soft silicone strap (other bands are available, and fit both devices).

Fitbit sense v versa