fitbit flex jawbone up

Kevin Smith/Business Insider

The Fitbit Flex (left) and Jawbone Up.

Wearable tech is all the rage these days.

Fitbit and Jawbone recently launched new digital wristbands that motivate you to stay active.

These devices track how many steps you've taken in a day, how many calories you've burned, and the distance you've traveled.

The Fitbit and Jawbone stand out from other fitness bands by tracking your sleep. The devices then help you to figure out how to wake up more rested. An added bonus is the vibration motor that can silently wake you up from sleep so you don't disturb your partner.

Both the Fitbit Flex and Jawbone Up have their positives and negatives. But which one is better and why?