For about two weeks or more between May and June 2020, I was able to cast my entire desktop screen to my Chromecast device and get the ability to extend my desktop (not duplicate it) to the TV where I've got my Chromecast device installed. I thought, finally the Google developers have added this much requested feature to the Google Chrome browser's cast functionality! This was extremely useful to me, because I effectively had two separate screens to arrange my windows on--double the video real estate. Although the mouse moved somewhat slowly on the second extended Chromecast screen (the one on the right in the screenshot below), the audio and video on the TV were well synchronized. Somehow, the feature no longer appears for me this week when I go to cast my desktop from the Chrome browser. How can I get this functionality back?

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6 Answers 6


Yes the procedure described in the article is not working on recent Windows 10 version. The trick is to make Windows believe that an external screen is connected. I confirm that the BelegNeurion solution works nicely! This is my favorite solution (neat, no hardware required) but it requires device driver installation and the screen resolution is fixed to 1920x1080. It's a "geek" solution.

Another solution is to connect a dummy connector to the hdmi port of the PC (Amazon has plenty of them). Resolution can be set up to 4K. An HDMI to VGA connector also works, in this case the resolution can be change up to 1920x1080. And finally Dummy connector for VGA and USB C also exists.

Note: I also tried SpaceDesk: it works, but is much slower than chromecast (not suitable for video) and the sound is not transmitted to the TV.


than If you have an Android-based TV - try to use Spacedesk app: https://spacedesk.net/ Server part app - on PC, client|viewer - on TV.

Technically, it works better than Chromecast and has more features.

  • I's not an Android-based TV. It's a regular TV with a Chromecast device. Jun 22, 2020 at 16:30
  • Thanks I did not know about that! Aug 12, 2022 at 8:21

Windows 10 20H2 Build 19042.870

First off, using Chrome to Cast to your 2nd monitor/display via the extend is working fine! Disclaimer here is: Windows NEED to detect your 2nd monitor/display. If Windows do not detect yr 2nd monitor/display, Chrome Cast will not be able to cast from 2nd monitor/display.

What you can do is to purchase a DUMMY VGA/HDMI/USB C plug to fool Windows into thinking you hv a 2nd monitor/display connected. Then in Windows, EXTEND your display.

Start Chrome, click Cast, Cast Desktop, Click Chromecast Device to Cast, Select Which Screen to Share (remember to enable share audio)

That's all. This is as per @ShieldOfSalvation posting!

  • 1
    The "Share audio" checkbox is something new I just began to notice today! I don't believe I had seen that before. In fact, it's not in the screenshot that I posted earlier, titled "Share your entire screen". It's a new checkbox that appears at the bottom left of that dialog box. Apr 14, 2021 at 22:05

I found the solution!

CAVEAT: If simply trying the steps below won’t pull up the second screen in step 6, then you must convince Google Chrome that there is a second screen. Here’s where a dummy HDMI plug, “headless ghost”, or other display emulator comes in handy if you do not have an actual second screen.

NOTE: it seems a few PCs actually behave as though a monitor is connected, and won't need a dummy HDMI plug. I'm not quite sure if this has to do with these ports behaving as analog ports. A machine that I've found does not need an HDMI dummy plug is the HP EliteBook 8470p.

Some examples of dummy HDMI plugs are:

To convince Google Chrome that there is a second screen,

A. Plug in either a real HDMI cable or a dummy plug into the computer's HDMI port. If using a real HDMI cable, you must plug the other end into an actual monitor or TV.

B. Follow steps 1 – 2 below.

C. Confirm that you have a visible extended desktop on your second screen by switching its input source to that second HDMI port.

D. Perform steps 3 - 5. Note that step 6 won’t be possible at this stage as your screen will appear on the Chromecast, just not extended as a second separate display.

E. Repeat steps 3 – 5 again, just to stop the Chromecast.

F. Repeat steps 3 -5 a third time and voila! Step 6 is now possible.

Assuming your computer is convinced that it has a second screen attached, then to extend your desktop with Google Chromecast,

  1. Make sure to hold down the Windows button on your keyboard and press P.
  2. Then select Extend from the right flyout menu that should appear (this is what will open up the second monitor as an option for you to extend your desktop in the next few steps!) enter image description here
  3. After that, proceed to your Google Chrome browser on your PC and click the three-dot menu at top right and select Cast...
  4. A popup menu will appear, but don't select your Chromecast device just yet! Instead, at this point you will choose what source content to cast. Hover over to the bottom of the popup menu and click the Sources button, and from its drop-down list select "Cast desktop" so it becomes checked. enter image description here
  5. Now you can click in the popup menu on the name of the Chromecast device to which you want to cast your screen. IMPORTANT: avoid switching steps 4 and 5 around because you can inadvertently cast the wrong source content to your device!
  6. You will then be presented with a choice of Screen 1 or Screen 2 which you will cast to the Chromecast device, so choose Screen 2 here and click Share. That's it! enter image description here

NOTE - You can also make the Cast button remain on the Chrome browser toolbar always for easier access (otherwise it will disappear later and you'll have to find the feature again hidden under the three-dot menu.) To keep the Cast button always on the toolbar, right-click the Cast button on your toolbar after you've already begun casting per the above steps. The choose, "Always show icon".

Some caveats about extending your desktop via Chromecast, from my experience:

  • You may experience a slight video lag on the extended monitor; I say it is negligible considering the advantages you gain by this feature (you just shouldn't expect high performance screen refresh rates on it!)
  • At times, when you are not using (casting to) the second monitor, certain popup windows may try to appear on that side and leave you clueless unless you either re-display the extended desktop or use the Windows + P keyboard combination and switch to "PC screen only".
  • This is no longer working on Windows 10 2004
    – daviddgz
    Oct 30, 2020 at 7:11
  • 2
    I found a solution for Windows 10. The trick is to add a virtual display and then use Chromecast to stream to that display. To create the display, install this driver: amyuni.com/forum/viewtopic.php?t=3030. You will then see another display in Display settings. Set that to extend. Now you can stream to that display via Chrome. Dec 12, 2020 at 9:14
  • My answer above is indeed still working for me on Windows 10 Version 10.0.19041 Build 19041 with plain old Google Chrome Version 87.0.4280.88 (Official Build, 64-bit). I would stay away from downloading third-party software drivers to make your Chromecast work--especially from unknown sources like the proposed amyuni.com. Dec 12, 2020 at 21:04
  • 1
    This can only ever work if your PC is, for whatever reason, detecting a second display, I think?
    – Daniel B
    Dec 16, 2020 at 12:13
  • This doesnt seem to be working for me. No matter how many times I do windows + p and then extend, when I click on my tv it automatically casts without asking me Screen 1 or Screen 2.
    – Bill
    Jan 26, 2021 at 11:34

Apologies for not finding this post in time, here is my video from 2016 https://youtu.be/rMPAlWMvfsY Still works, just need a dongle.

In short - You can fool you need a Dongle from HDMI/DVI/DP/USBC to VGA, VGA is the key as it is an analog signal that the computer cant check for, so when you have a VGA dongle and hit detect displays, it will add a new display, without it being there, from there you can use that extra screen to be set to be cast to Chromecast, Teamviewer or any other share medium.

  • While this link may answer the question, it is better to include the essential parts of the answer here and provide the link for reference. Link-only answers can become invalid if the linked page changes. - From Review Nov 1, 2022 at 6:13

I ran into the same scenario with my laptop... I have seen some answers regarding the VGA monitor port, and forcing your OS to think that you have a second display, but I do not have a VGA monitor port (only an HDMI), so this was not an option. If you are wanting to use your extended display just to monitor something in the background, but you are working on your main screen, I may have a good answer for you, without having to buy any additional equipment (dummy adaptors, etc...). I didn't like the idea of having a dongle plugged into my laptop every time I wanted to extend the screen.

If you hold down your Windows key + Tab, you can create another desktop. After you create a new desktop, open Chrome on the new desktop to whatever page you are wanting and cast it through Chrome. Then, use your Windows + Tab function again and go back to your original desktop you were working on. Now, you are casting the content from your other desktop, while independently working on your original desktop. Though you are not truly "extending" your display, you can monitor content in the background on your 2nd display. Hope this helps!!

  • I hadn't tried your Windows key + Tab idea before, but it does create a separate virtual desktop for me which is useful in its own right. As you said, however, this virtual desktop just doesn't extend my display onto a second monitor using the Chromecast. Bummer! Great idea, though, for someone that just needs the extra real estate but doesn't need to see both screens simultaneously. Mar 4, 2021 at 14:12

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