Spotify Hifi, the lossless music feature, is still being worked on according to recent UI leaks and prompts.Spotify announced Hifi in 2021 but it has not been released yet, while rivals already offer similar features.Rumors suggest a possible rebranding of Hifi to a $20-a-month plan called 'Supremium'.Screenshots shared by a Reddit user reveal dialog prompts and system settings related to Spotify HiFi.