Do smartwatches and fitness trackers work on Linux?

The first thing to understand is that a smartwatch is a phone accessory. Your Apple Watch, Garmin, Fitbit or Galaxy Watch talks to the app on your phone over Bluetooth, and the phone talks to the maker's servers. Your computer is not part of that chain. Switching your PC to Linux does not interrupt it, and your steps, your sleep and your workouts keep recording exactly as before.

Where you notice a gap is on the desktop. Garmin Express, the Fitbit desktop app and Samsung's Windows software are Windows and Mac programs with no Linux version. If you use one of those to load maps onto a watch, to run a firmware update over a cable, or to export data in bulk, that workflow needs replacing. For Garmin in particular, many devices appear as a plain USB drive when plugged in, which lets you copy activity files and route files across by hand, and most syncing can be done from the phone app instead.

Web dashboards cover most of the rest. Garmin Connect, Fitbit and Strava all work in Firefox or Chrome on Linux, so looking at your history, planning routes and exporting data are all still available, just in a browser rather than an installed program.

On the phone side there is a well-known open-source alternative called Gadgetbridge, an Android app that pairs and manages a long list of watches, bands, rings and headphones without the vendor's own app. It covers Amazfit, Fossil, Garmin, Huawei, Pebble, Sony, Xiaomi and many others. It is Android only and does not support Apple Watch, so it is not a way to manage a watch from your desktop. It is worth knowing about if you are also trying to get away from a vendor's phone app.

Apple Watch is the firmest no for desktop involvement. It requires an iPhone, and there is nothing on Linux that changes that.