To cast from Firefox to Chromecast, install the fx_cast Firefox extension and its companion bridge application. This combination is the only reliable way to cast video and audio directly from the Firefox browser to a Chromecast-connected TV.
How to cast from Firefox to Chromecast with fx_cast
Firefox does not include built-in Chromecast support, so you need two tools: the fx_cast extension for Firefox and the fx_cast companion bridge application. The extension sends the cast command, while the bridge app runs on your computer to handle the communication with your Chromecast device. Both are required for the process to work.
Install the fx_cast Firefox extension
- Open Firefox and go to the browser's add-ons store.
- Search for "fx_cast".
- Click the button to add the extension to Firefox.
- Confirm the installation when prompted.
The extension will appear in your browser's toolbar after installation. You will need to restart Firefox to activate it.
Download and install the companion bridge app
The companion bridge application is mandatory. Without it, the extension cannot discover or connect to your Chromecast. Download the correct version for your operating system from the fx_cast project page. The app is available for Windows, macOS, and Linux. Install it like any other application on your system, then leave it running in the background whenever you want to cast.
Cast a video from Firefox to your TV
After installing both the extension and the bridge app, restart Firefox. Navigate to a webpage containing a video. Look for the cast button in the video player controls, it typically appears as a small rectangular icon with a Wi-Fi-like signal in the corner. Click the cast button, and a list of available devices will appear. Select your Chromecast from the list. The video will begin playing on your TV, and you can control playback (play, pause, volume) from the Firefox browser.
Alternative methods: screen mirroring and HDMI
When fx_cast cannot be used, you have two workarounds. The first is device-level screen mirroring. On Windows, press Win + K to open the Miracast connection panel. On macOS, open Control Center and select Screen Mirroring. Android users can go to Quick Settings and choose Cast or Smart View. iOS users can access Screen Mirroring from Control Center. These methods mirror your entire screen, including Firefox content, to the TV. The second workaround is a wired HDMI connection, which offers maximum stability and works with any computer that has an HDMI output.
Troubleshooting common fx_cast problems
If casting fails, check your network stability first. Your computer and Chromecast must be on the same Wi-Fi network. Restart Firefox after installing both the extension and the bridge app, this is a frequent fix. Ensure your Chromecast firmware is updated to the latest version through the Google Home app. If audio or video quality is poor, verify that your Wi-Fi signal is strong and free from interference. For device compatibility issues, confirm that your Chromecast model is supported by the fx_cast project. If you also use a device that supports Chromecast on Roku, note that the fx_cast method is specific to Google's Chromecast hardware. If you need to set up your Chromecast on a new Wi-Fi network, complete that setup in the Google Home app before attempting to cast from Firefox.
