So far, Amazon’s new Fire TV interface has only been pushed out to the Fire TV Stick Lite and Fire TV Stick 3 that were released last year. It won’t be that way for much longer because we now know that the Fire TV Stick 4K, the Fire TV Cube (both 1st and 2nd gen), and the 3rd-gen Fire TV (pendant) are next in line to get the interface update, according to Protocol. Those four Fire TV models should be updated to the new interface in March.
This means that, by April, all stand-alone Fire TV models released since 2017 should be eligible to receive the new interface. All Fire TV Edition televisions, the 2nd-gen Fire TV, and the 2nd-gen Fire TV Stick will receive the interface update sometime after March. As previously stated, the 1st-gen Fire TV and the 1st-gen Fire TV Stick, both released in 2014, are the only models that will never receive the new interface. If you’re not sure which Fire TV model you have, either install my Informer app and it will tell you, or see this article for unique characteristics of each model.
The new Fire TV interface will arrive through a standard over-the-air software update. Fire TVs automatically check for and install software updates while they aren’t being used, so you’ll likely wake up your Fire TV one day and find that the new interface has been installed. There is no way to manually install the update early, but you can manually check if it’s your device’s turn to receive the update by going to Settings > My Fire TV > About > Check for Updates.