SM-R866U firmware

Stock firmware and official updates for the Samsung Galaxy Watch FE (SM-R866U), by region.

Software support

Update policyQuarterly security updatesOn Samsung's current security update list

Latest firmwareAndroid 16R866USQS2BZG3 · built Jul 24, 2026

RegionBuildAndroidSecurity patchDateDetails

United States XAABuildR866USQS2BZG3AndroidAndroid 16Security patch—BuiltJul 24, 2026DetailsDownload

Builds in our firmware catalog, newest first.

BuildAndroidBuiltRegions

R866USQS2BZG3AndroidAndroid 16BuiltJul 24, 2026Regions1 CSC

R866USQS2BZE1AndroidAndroid 16BuiltMay 20, 2026Regions1 CSC

R866USQU2BZB6AndroidAndroid 16BuiltFeb 11, 2026Regions1 CSC

R866USQS1BZA2AndroidAndroid 16

Taken from the SM-R861; this model can differ (chipset, network bands).