Fitbit Inspire 3

Fitbit Inspire 3 is an armband from 2022, sitting in the budget band at an indicative $99.

It reads 17 of the 33 signals this comparison tracks. Nothing at all from body composition. Rarer readings it does take: sleep efficiency.

By sensor class: 1 at clinical grade and 13 at consumer grade. That grade is my classification of the hardware, not a lab test. Those readings come from an optical heart rate sensor, an optical blood oxygen sensor, a skin temperature sensor and an accelerometer. Blood oxygen is measured through the night, not continuously through the day.

Its 10 days per charge are the 4th longest of the 11 devices of its kind here that publish a figure. The AMOLED screen can stay always on. No GPS of its own, it borrows the phone's. Rated 5ATM / 50m, fine for swimming. No subscription is required.

Entry slim tracker; SpO2 + skin-temp, no ECG/altimeter, connected GPS only.