Hi Soloeuph From Firefox for Android you can send video URLs to your Chromecast, here's how: https://support.mozilla.org/en-US/kb/use-firefox-android-send-videos-chromecast There is no Chromecast support in Firefox for Mac, Windows, Linux or iOS If the above doesn't help please let us know what you did, what happened, and what you expected as well as your device (mac, windows, linux computer model, Android tablet or phone model, iPhone or iPad model) and your device's operating system (e.g. Windows 7, Android Lollipop, iOS 9.0.2, Mc OS X Mavericks 10.10.5 etc) Cheers! ...Roland