Check out the manual for Loudness Penalty. It has a table that says what the different services do.
So, for example, Spotify enables normalization by default, they target -14 LUFS, use limiters, normalize both tracks and albums, and will turn up quiet tracks. Amazon, by contrast, does not use limiters, does not turn quiet tracks up, only normalizes at the track level, and so forth . . .
So, for example, Spotify enables normalization by default, they target -14 LUFS, use limiters, normalize both tracks and albums, and will turn up quiet tracks. Amazon, by contrast, does not use limiters, does not turn quiet tracks up, only normalizes at the track level, and so forth . . .