Roku devices are primarily designed to stream content over the internet, so an active internet connection is essential for accessing most of the channels and features available on Roku. However, there are some limited capabilities you can utilize without an internet connection. For instance, if you have downloaded content from certain channels, you may be able to access and view that content offline.
Additionally, if you have a Roku TV, you can still use basic features, such as watching live television through an antenna connected to the TV, without needing an internet connection. Some Roku devices also allow for local media playback via USB or from a local network if they have been properly configured while connected to the internet initially.
For further details about the specific capabilities of your Roku device without an internet connection, it is recommended to check the user guide or the official website of Roku for the best information.