Explainers
These 7 are the questions that come back again and again in owner discussion. Each leads with a short answer, computes its numbers from the catalog, and names the maker or regulator page behind anything it quotes. None of it is medical advice.
Because the headline is measured with the screen asleep between glances. Where makers publish both figures, turning the always-on display on leaves a median 39% of the headline in this catalog, and a GPS workout drains faster still.
Read the full answer →Every watch here needs a phone to set up and to sync. Away from it, 9 have an LTE version for calls and messages, 28 store music, and 6 combine LTE, music and contactless payments.
Read the full answer →No watch here needs a subscription to work. 41 of 53 come from makers that sell an optional paid tier; what it gates ranges from video classes to coaching and deeper analysis.
Read the full answer →Only 4 of 53 watches here have a published update promise, from 3 to 5 years. The rest are 'not published'.
Read the full answer →A cleared feature has an FDA decision behind the specific claim it makes; 17 watches here carry at least one, 15 of them an ECG. Heart rate, blood oxygen, VO2 max and sleep scores are wellness estimates.
Read the full answer →A rating is a lab pressure test, not a promise for every use. Apple's own footnote says a 50-metre watch suits swimming in a pool or ocean but not scuba diving, waterskiing or other high-velocity water sports, and that resistance can diminish over time.
Read the full answer →Bigger cases hold bigger batteries and weigh more. 16 watches here come in more than one size; the lightest case in the catalog is 21 g (Polar Ignite 3).
Read the full answer →For the specifications themselves, what each number on a watch page means and which of them can be compared, see how to read a smartwatch spec sheet, where every figure is computed from this catalog.