Tubi is compatible with all models of Roku platforms except for 1st Generation Roku models.

Please check out the information in this link: Roku Models

If you look at the table under the "Critical Reception" > "Feature Comparison" section you'll find the list of all of the different kinds of Roku models that exist.

While the latest Roku models are the most reliable, we support all of the Second, Third, and 4th generation devices.