Designed for the fourth and fifth-generation Apple TV models, the new tvOS 13.3developer beta can be downloaded onto the Apple TV via a profile that's installed using Xcode.
tvOS updates (aside from major releases) have historically been minor in scale, focusing on under-the-hood bug fixes and improvements rather than major outward-facing changes. Apple provides little to no information on what's included in tvOS beta updates, so we may not discover anything new after installing the software.
In tvOS 13.2, for example, Apple's only available information was that it included general performance and stability updates.
While we don't often know what's new in tvOS during the beta testing process, we let MacRumors readers know when new updates are available so those who are developers can download it upon release.
If we find anything new in the tvOS 13.3 beta, we'll update this article.