4K HDR video on Roku is currently available from Netflix, YouTube, Amazon and FandangoNow. Apps with 4K (but not HDR) support include Vudu, Plex, UltraFlix, Toon Goggles, 4K Universe and Smithsonian, as well as a few other niche apps. No other platform can match that selection.

https://www.cnet.com/products/roku-streaming-...us/review/