Fire OS is the operating system Amazon develops for its own Fire TV devices (Fire TV Stick, Fire TV Cube) and for Fire tablets, as well as, in some markets, for third-party smart TVs with Fire TV built in.
The basics: an Android fork
Fire OS started as an Android fork: it shares the same open-source core, but Amazon has heavily modified it to fit its own business strategy. The most obvious difference is that it doesn’t include the Google Play Store: apps are installed through the Amazon Appstore, a separate store with its own review and publishing process. The major streaming apps (Netflix, Disney+, Prime Video, YouTube, Spotify) are all reliably available, given the mutual commercial interest in being present on such a widespread platform, but the overall catalog of less common apps can differ from Android TV or Google TV, and some developers choose not to publish on this alternative store at all.
What sets it apart
Fire OS’s interface is built around two elements: Alexa, natively integrated into the remote and the system (voice search, control of compatible smart home devices, setting reminders and alarms), and Prime Video content, which unsurprisingly takes a prominent spot on the home screen for an Amazon product also aiming to reinforce Prime subscriptions. This isn’t a performance limitation: smoothness depends on the specific device’s hardware (the chip, available RAM), not the operating system itself, and a high-end Fire TV Stick can be more responsive than a budget Android TV device with lower-tier hardware.
Don’t confuse it with Android TV/Google TV
While both are Android-based, Fire OS and Android TV/Google TV are separate ecosystems with separate app stores and catalogs that don’t fully overlap. A Fire TV device doesn’t natively run apps built for Android TV, and vice versa: an app has to be explicitly published on both stores to be available on both platforms, even though the underlying Android code is largely shared between the two versions.
