What’s on display?: Most smartwatches have full-colour displays, though the underlying technology will determine how good the screen looks. There has been a move towards AMOLED (active matrix organic light emitting diode) displays, as used in the Apple Watch which present a bright screen, crisp text and accurate colours. Fitness trackers tend to have lower-quality screens and may not present in full-colour, partly to save battery life.
Our top pick for most people is the Apple Watch Series 4 with GPS (starting at $399), which has a huge display, ultra-fast processor, Raise to Speak Siri, fall detection and a built-in electrical heart rate sensor for taking on-the-go electrocardiograms. It also runs watchOS 5, which makes the watch even more useful with automatic workout-tracking, offline podcast playback and a Walkie-Talkie voice chat feature.