The new 18.104.22.168 software update that is currently rolling out to the Amazon Fire TV Stick 4K has added support for screen mirroring through the Mircast standard. This allows customers with compatible phones, tablets, and computers to wirelessly mirror their device’s screen to the Fire TV Stick 4K, as if it were an attached monitor. Screen mirroring support was available on earlier Fire TV models, such as the Fire TV Stick 2 and Fire TV 2, but was dropped when Fire OS 6 arrived on the Fire TV 3. This latest Fire TV Stick 4K software update marks the first time screen mirroring has been made available on modern Fire TV hardware and Fire OS 6.
The easiest way to enable screen mirroring on the Fire TV Stick 4K, or any Fire TV model that supports it, is to use the Fire TV shortcut menu. You bring up the shortcut menu by simply holding the home button on your remote for a few seconds. The shortcut menu will appear regardless of what the Fire TV is currently doing, so it works if you’re in the Fire TV interface or in a 3rd-party app.
It’s also possible to enable screen mirroring form the Fire TV’s Settings. This can be done by navigating to Settings > Display & Sounds and scrolling down to the new “Enable Screen Mirroring” option. It makes no difference whether you use the shortcut menu or the settings menu to enable the feature. Once enabled, the Fire TV will display a message informing you that it is waiting for a mirroring connection. Pressing any button on the remote will cancel the mirroring session.
For mirroring through this new Fire TV feature to work, the device doing the mirroring needs to support a standard called Miracast. Unfortunately, support for Miracast on mobile devices and computers seems to be disappearing. Apple devices have never supported Miracast and Google has dropped support for Miracast from Android 9 Pie. Windows 8 and Windows 10 computer usually support Miracast. Older Android phones and tablets that support Miracast will have an option to enable a wireless display in either the Cast or Display options menu. Select Amazon Fire tablets also support screen mirroring through Miracast.
Screen mirroring protocols that are most ubiquitous, like Google Cast and Apple AirPlay, are closed and proprietary formats. Google and Apple do not freely allow any manufacturer, like Amazon, to support those protocols, so this new screen mirroring option for the Fire TV Stick 4K will not allow you to use the Google Cast or Apple AirPlay functionality of Android and iOS devices. There are 3rd-party mirroring apps for Fire TV that add support for Google Cast and Apple AirPlay, such as AirReceiver, which is the one I use, but these apps are a bit flakey because they have to reverse engineer the closed protocols, so they never work quite as seamlessly as something like a Chromecast or Apple TV.