Altimeter
YesGPS
YesHeart rate
Chest strap compatibleWaterproofing
-Notifications
-Waterproof
YesClock
YesSleep tracking
-Companion app platforms
-Altimeter
NoGPS
NoHeart rate
NoWaterproofing
-Notifications
-Waterproof
Water-resistant (50m)Clock
YesSleep tracking
YesCompanion app platforms
-Altimeter
NoGPS
NoHeart rate
-Waterproofing
-Notifications
-Waterproof
Water-resistant to 150ftClock
YesSleep tracking
YesCompanion app platforms
iOS, AndroidAltimeter
NoGPS
NoHeart rate
No (but works with 3rd party trackers)Waterproofing
-Notifications
-Waterproof
Yes (3 meters)Clock
-Sleep tracking
-Companion app platforms
-