Amazon launched Vega OS on the Fire TV Stick 4K Select. Here are five things that actually change for users, from sideloading to app compatibility.
Amazon has used a customized version of Android to power Fire TV devices since 2014. That era is ending. In September 2025, Amazon officially announced Vega OS, a new Linux-based operating system built entirely in-house, and launched it first on the Fire TV Stick 4K Select in October 2025.
The shift goes deeper than a software update. Vega OS replaces the Android foundation entirely, changes how apps are built and distributed, and removes the flexibility that Fire OS users have relied on for years. Here is what actually changes.
1. Sideloading is Gone for Everyday Users
This is the change that affects the most people. Fire OS, being Android-based, allowed APK sideloading through tools like Downloader and ADB. That made Fire TV one of the most flexible streaming devices available, especially for users running IPTV apps or custom setups.
Vega OS closes that door for ordinary users. Amazonโs own product page states that only apps from the Amazon Appstore are available for download on Vega OS devices. The standard Downloader app and the familiar โInstall from unknown sourcesโ toggle are both gone.
Technical sideloading via USB command line is possible, but only for registered Amazon developers with the device enrolled under a developer account. That is not a practical workaround for everyday users.
Existing Fire OS devices continue to support sideloading. But Amazon has confirmed all future Fire TV Stick models will ship on Vega, so the window on that flexibility is closing.
2. Performance on Low-End Hardware Gets a Real Improvement
The Fire TV Stick 4K Select ships with just 1GB of RAM. Previous Fire TV Stick 4K models carried 2GB.
That sounds like a downgrade, but Vega OS is designed around that constraint. Instead of each app bundling its own software framework, Vega OS bakes shared libraries directly into the operating…