Types
6 kinds of smartwatch
The type decides how often you charge, how much the watch does without your phone, and what it weighs on the wrist. The lines blur at the edges; each watch is filed under what its maker builds it around.
Fitness
12 models from 4 makers, ~$80–$700
Fitness watches put heart rate, sleep and training metrics first and keep the app layer thin. Most pair with either iPhone or Android, and most run several days between charges even with an AMOLED screen. What separates them is GPS quality, maps, and whether the maker charges for the deeper analysis.
Rugged outdoor
12 models from 7 makers, ~$250–$1,000
Thick cases, military-standard claims, buttons usable with gloves, and battery quoted in weeks, often with a solar figure on top. Several use memory-in-pixel screens that are always on by design, which is why their always-on figure is the same as their headline.
Running
10 models from 5 makers, ~$249–$750
Running watches are built around GPS pace and training load. Expect physical buttons, multi-band GPS on the newer models, structured workouts and race predictions. Battery is quoted in GPS hours as much as days, and that GPS figure is the one to compare.
Multisport
8 models from 4 makers, ~$349–$1,100
The premium all-rounders: triathlon modes, full topographic maps, dual-band GPS, and the longest feature lists in each maker's range. They are heavier and dearer than running watches, and their headline battery figures come with a long list of modes, so the GPS and multi-band figures matter more than the smartwatch claim.
Everyday smartwatch
7 models from 4 makers, ~$249–$500
These run a full app platform, Apple's watchOS or Google's Wear OS, so they do the most away from the phone: replies, maps, payments, third-party apps, and on LTE models calls without a phone nearby. The cost is the battery. The headline figures assume the screen sleeps between glances, and the makers' own always-on figures are shorter. They are also the most tied to one phone ecosystem.
Hybrid
4 models from 2 makers, ~$250–$600
Hybrids put analog hands over a small screen. They look like a watch first, track heart rate and sleep, and run for weeks, but give up maps, apps and most workout screens. The Withings models carry FDA-cleared ECG in a body that does not look like a gadget.