Hello. 

I recently bought a 4k SHarp tv with built in Roku TV. 
My goal is to cast 4k videos I find on my windows PC to my tv and be able to see them in 4k. 
I have been able to use chrome on my PC to cast 4k youtube videos only. When you visit youtube on your chrome PC browser you get the cast icon at the top to show you an option to cast to TV "youtube" and then you select that and it opens the youtube app on the TV and it works perfect for 4k. I understand that basically this is a web address being sent to the app on the roku tv. 
The problem I have is if I am on any other website other than youtube in which there is a video I want to cast or just the tab on my browser, then there is no option to cast to TV when you click on the cast icon. So, how do you cast or watch videos you find online on your computer to your TV so you can watch in 4k without having to buy a Chromecast Ultra?

I have tried the screen mirroring and it works, but I get lag and the 4k content does not look very sharp to me compared to casting to the youtube app on the tv in 4k. 

Any way to do this with the Roku Tv installed in my tv already?

Any suggestions appreciated it!! thanks

Casting from a Windows computer rarely works. Part of it is the hardware requirements for the Windows computer, and the other may or may not be a Roku issue. I've cast from my Android phone with no issue, but have never been able to get Mirrorcast to work from a Windows PC. 
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What is the source of the 4K material? Why can't you use a channel/app on the Roku to play the material?
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I also question if you can "cast" something in 4K if the computer itself doesn't have a 4K display. No idea if it works, just wondering. 

Timewilltell wrote:

Hello. 

I recently bought a 4k SHarp tv with built in Roku TV. 
My goal is to cast 4k videos I find on my windows PC to my tv and be able to see them in 4k. 
I have been able to use chrome on my PC to cast 4k youtube videos only. When you visit youtube on your chrome PC browser you get the cast icon at the top to show you an option to cast to TV "youtube" and then you select that and it opens the youtube app on the TV and it works perfect for 4k. I understand that basically this is a web address being sent to the app on the roku tv. 
The problem I have is if I am on any other website other than youtube in which there is a video I want to cast or just the tab on my browser, then there is no option to cast to TV when you click on the cast icon. So, how do you cast or watch videos you find online on your computer to your TV so you can watch in 4k without having to buy a Chromecast Ultra?

I have tried the screen mirroring and it works, but I get lag and the 4k content does not look very sharp to me compared to casting to the youtube app on the tv in 4k. 

Any way to do this with the Roku Tv installed in my tv already?

Any suggestions appreciated it!! thanks

The casting you're talking about is the opening of an app on the remote device (Roku TV in your case) from the casting device (your PC). Screen mirroring is how you get what you want, and you've discovered the lag that comes with that.

When I want to cast a browser tab to my computer, I use a Chromecast device and the Chrome browser. They are designed to work that way. And, yes, there's a small lag when doing that. It's the nature of the beast.

The closest approximation of Chrome-to-Chromecast tab "casting" is screen mirroring.

DBDukes wrote:

The casting you're talking about is the opening of an app on the remote device (Roku TV in your case) from the casting device (your PC). Screen mirroring is how you get what you want, and you've discovered the lag that comes with that.

When I want to cast a browser tab to my computer, I use a Chromecast device and the Chrome browser. They are designed to work that way. And, yes, there's a small lag when doing that. It's the nature of the beast.

The closest approximation of Chrome-to-Chromecast tab "casting" is screen mirroring.

Hi DBDukes, 
I have a chromecast (the old key looking type) and that works for casting tabs no problem. Only it won't work with 4k content so I would have to pay to get the Chromecast Ultra at around $70 I figure there should be another way to get this done without having to buy yet another device to cast. 
I tried connecting an HDMI cable from la Laptop to the TV and use it as giant screen for the laptop. There is unnoticeable lag and all works well, but I can't seem to see a difference between a video played at 4k and the same video played at 1080p. I wonder if this is a limitation of my laptop that can't send the 4k signal via HDMI to the TV since my laptop is a 1080p resolution. Not sure if I need a dedicated graphics video card in the laptop or maybe upgrading the laptop to an 8th gen intel with integrated video will send 4k to the tv OR if all that I just said is just wrong. 
Any thoughts? thanks

Timewilltell wrote:

...
I tried connecting an HDMI cable from la Laptop to the TV and use it as giant screen for the laptop. There is unnoticeable lag and all works well, but I can't seem to see a difference between a video played at 4k and the same video played at 1080p. I wonder if this is a limitation of my laptop that can't send the 4k signal via HDMI to the TV since my laptop is a 1080p resolution. Not sure if I need a dedicated graphics video card in the laptop or maybe upgrading the laptop to an 8th gen intel with integrated video will send 4k to the tv OR if all that I just said is just wrong. 
...

The best output you'll get is via the HDMI that you tried. You may be able to get wireless mirroring or casting to work, but it will never look better than direct cable output. If your computer can't handle 4K, you won't get 4K output from it, whether wired or wireless.

The question by atc98092 is worth answering:

atc98092 wrote:

What is the source of the 4K material? Why can't you use a channel/app on the Roku to play the material?...

Sure, not everything has a Roku app, but a lot do.

Casting and mirroring will get different results..

Casting in the Chromecast sense of the word is just basically pointing the casting device directly to the web content.. it usually works great.

Mirroring or casting from a web tab takes an extra "hop" because not only do you have to download the content to your PC, but then it has to be re-broadcast from the local PC to the streaming device.. lots of poor video quality and sound stuttering are the usual result of mirroring.. unless Google has "fixed" this since I've last done it, that is.

Timewilltell wrote:

DBDukes wrote:

The casting you're talking about is the opening of an app on the remote device (Roku TV in your case) from the casting device (your PC). Screen mirroring is how you get what you want, and you've discovered the lag that comes with that.

When I want to cast a browser tab to my computer, I use a Chromecast device and the Chrome browser. They are designed to work that way. And, yes, there's a small lag when doing that. It's the nature of the beast.

The closest approximation of Chrome-to-Chromecast tab "casting" is screen mirroring.

Hi DBDukes, 
I have a chromecast (the old key looking type) and that works for casting tabs no problem. Only it won't work with 4k content so I would have to pay to get the Chromecast Ultra at around $70 I figure there should be another way to get this done without having to buy yet another device to cast. 
I tried connecting an HDMI cable from la Laptop to the TV and use it as giant screen for the laptop. There is unnoticeable lag and all works well, but I can't seem to see a difference between a video played at 4k and the same video played at 1080p. I wonder if this is a limitation of my laptop that can't send the 4k signal via HDMI to the TV since my laptop is a 1080p resolution. Not sure if I need a dedicated graphics video card in the laptop or maybe upgrading the laptop to an 8th gen intel with integrated video will send 4k to the tv OR if all that I just said is just wrong. 
Any thoughts? thanks

Even with a Chromecast Ultra, you can't cast a tab at 4K. And it is likely your computer limits 4K output over HDMI if you are playing any type of restricted content (Netflix, etc).

It seems that my best bet is to just use an HDMI cable to use the 4k TV as my screen. I have a newer laptop that has an 8th gen intel i5 that can handle the 4k output well and 4k videos look perfect and smooth, so I just ordered a long HDMI cable and will see how that works. 
I am not spending $70 to get the ultra chromecast, but good to know that it won't even cast a tab in 4k, which would have been the only reason to buy it.