NOTE: This article was originally published with just Windows information. The information on how to extend your desktop on a Mac was added on August 3, 2016.
Google Chromecast mirrors your display from an Android device, an iPhone, iPad, Mac, Windows PC, or Chromebook. “Mirroring” means having another device show your screen exactly as you see it on your computer or mobile device. However, you can also extend your desktop surface, not just mirror it. This can be more useful in a lot of situations–you’re opening up a whole new screen to use as a second desktop. (It’s like being able get a second desk when your first desk is too covered in papers to work on.) However, using Chromecast to extend your desktop or laptop screen requires some minor effort on your part. This article will cover the process for both Windows computers and Macs.
Here are the steps needed to extend your display from a Windows 8 or Windows 10 desktop:
Extend Your Desktop from Windows with Chromecast
This walkthrough includes screenshots from Windows 10. However, this method of extending your display works with Windows 8 as well; you can follow the same steps for that Windows version.
- From the Start menu, select “Settings.” (An alternate route is to right-click on “Display Settings” on your desktop as a shortcut to get into System > Display.)
- In Settings, go to “System (Display, notifications, apps, power).”
- Once in Display, click on “Detect.” Here, we are going to trick Windows into thinking there’s a secondary display already attached, even though it isn’t. It says “Display not detected,” but shows a blue screen—click on it.
- Go down to “Multiple displays” and click the drop-down box. Then, select “Try to connect anyway on VGA.”
- Select display 2. In the drop-down box, select “Extend these displays.” Click the “Apply” button. A message will pop up and say, “Keep these display settings?” Click the “Keep changes” button.
Now you are ready to use the secondary display to extend your desktop surface with your Google Chrome browser and Chromecast.
- Open Google Chrome on your desktop.
- Before you can connect to your Chromecast with Click the Chromecast icon in the upper-right of your Chrome browser, you first need to click the small arrow on the Chromecast icon area. From there, scroll down to “Cast screen/window (experimental).” Then, select it.
- As the “Cast screen/window”, choose display number 2, the one we just fooled Windows into thinking we have. Now you should be able to see your Windows desktop on both your computer and your TV screen.
You now have an extended desktop surface. This allows you to move extra open windows, open programs, and applications between your desktop and TV screen.
Extend Your Desktop on a Mac
Now we’ll take a look at how to extend your Mac’s desktop screen through your Google Chromecast device.
Google Chrome Browser
In order to cast to your Google Chromecast from your Mac, you’ll need to download and install the most current version of Google’s Chrome browser. Chromecast support now comes built into the Chrome browser. (In the past, you would have needed to download and install a separate extension to use Chromecast.)
Once your Google Chrome browser is downloaded and installed, or open on your Mac, you’ll want to make sure you have the most current version.
To do this, click on Chrome in the upper left-hand corner of your screen. Then, select “About Chrome.” At the time of this writing, our version of the Chrome browser is 52. As long as your Chrome browser is up to date, when you select “About Chrome,” it will notify you that you are using the most current version of Chrome available. Otherwise, click on the button to get updates when given the option.
When your Google Chrome browser is up-to-date and ready to go, do the following:
- Click on the Google Chromecast icon in the upper right of your Chrome browser.
- Once the “Cast to” box opens, select the drop-down arrow. You’ll be presented with two choices: “Cast tab” or “Cast desktop.”
- Choose “Cast desktop.” You’ll be returned to the main Chromecast selection box.
- Next, select your Chromecast device. Ours keeps telling us it’s “Unable to mirror system audio” at this time.
- Another box pops up on the screen, asking, “Do you want Chrome Media Router to share your screen?” Click on the “Yes” button.
- Your Mac desktop should now be extended to where your Chromecast device is plugged in.
Keep in mind that the sound will still only be audible on your Mac, not on your extended display and sound set-up. We also noticed a slight lag in playback on our extended display, which is a large-screen TV.
Display extension will come in handy when you are working on something from your laptop or desktop and want to watch, look at, or work on something else on a bigger display like your television. Whatever your needs are for extending your desktop screen—work or pleasure—this is an excellent way to use the Chromecast to your advantage when you need a bigger desktop.