If you want to stream 4K contents, among Chromecast family (Chromecast, Chromecast Audio, and Chromecast Ultra), only Chromecast Ultra (update: and the Chromecast 2020, aka Chromecast with Google TV) has this capability.
But a lot of Chromecast Ultra owners found they cannot stream 4K contents with Chromecast Ultra.
What are the possible causes? What are the solutions?
This Chromecast guide first explains the requirements of using Chromecast to stream 4K contents, then show you the solutions for some problems related to streaming 4K contents with Chromecast Ultra.
The 6 requirements of using Chromecast Ultra to stream 4K contents
Chromecast Ultra is a very powerful streaming gadget.
You can use Chromecast Ultra to stream 4K Ultra HD contents with HDR. While normal Chromecast (Chromecast and Chromecast 2nd Generation) can only stream full HD contents (1080p) without HDR.
Although Chromecast does not require a 4K TV, there are a few requirements to meet if you want to use Chromecast Ultra to stream 4K contents, including:
- a 4K TV;
- fast internet connection (at least 10-20Mbps);
- HDCP 2.2 support;
- the original power adapter;
- a high-speed HDMI cable;
- 4K contents.
Among these 6 requirements, 2 are related to the TV: 4K resolution and HDCP 2.2 support. The other 4 are related to connection, content source and accessories.
Why is a 4K TV not sufficient for using Chromecast to stream 4K contents? You need a 4K TV with HDCP 2.2 support!
Chromecast Ultra actually works with any TV with HDMI input. It can scale video quality automatically for the TV it connects to.
A 4K TV is required only if you want to enjoy any 4K contents.
But when you want to enjoy 4K contents, then a 4K TV is not sufficient.
You need a 4K TV with HDCP 2.2 support.
This is the most tricky requirement of using Chromecast Ultra to stream 4K contents.
Most old TVs only support HDMI 1.4. And HDCP 2.2 is only available in HDMI 2.0.
Even more tricky, some HDMI 2.0 ports may not support HDCP 2.2. This depends on TV vendor’s implementation.
Most new 4K TVs should have at least one HDMI port with HDCP 2.2. You need to check the specs of the TV carefully.
But if you have an old 4K TV, or unbranded 4K TV, you may find you cannot use Chromecast Ultra to stream 4K contents,
If you connect Chromecast Ultra TV to an HDMI switcher or AV receiver, then the HDMI switcher or receiver must also support HDCP 2.2.
You must use the original power adapter to use Chromecast Ultra to stream 4K contents
The power adapter for Chroemcast Ultra has an Ethernet port.
You are NOT required to use the Ethernet connection. You can stream 4K contents with wireless connections.
But if you use other USB power adapters, Chromecast Ultra will detect it and will then stream contents in 1080p only.
The power output of the adapter you used does not matter. Google just wants you to use the bundled original power adapter if you want to use Chromecast Ultra to stream 4K contents.
Your internet connection speed should be fast enough
To use Chromecast Ultra to stream 4K content, you need a fast enough internet speed.
Normally, for 4K contents, the bandwidth (speed) required is at least 15-20mbps. You can test the maximum connection speed with Speedtest app.
If your internet speed is lower than 10Mbps, the streaming quality may be automatically scaled down to 1080p or even lower.
This requirement is consistent with other streaming devices, for example, Amazon TV. Actually, 10-20Mbps is required to stream 4K contents on any devices.
You need 4K content sources
Of course, to stream 4K contents with Chromecast Ultra, you need to have a 4K content source.
Most content providers now offer 4K contents. Some label them as 4K UHD. Netflix and YouTube have lots.
As mentioned, if your connection speed is not fast enough, or your TV does not support HDCP 2.2, then the streaming will be automatically scaled down.
I got a blank screen when I connect Chromecast Ultra to my TV? What’s the solution?
Normally, Chromecast Ultra should not give you a blank screen.
If something is wrong, it should show something in the screen telling you the problem.
Anyway, if you get a blank screen, you need to check:
- the color of the LED in the Chromecast Ultra. It should be solid white. If it is solid orange, you may try to power off Chromecast Ultra, then power it on.
- if Chromecast Ultra is connected to an HDMI switcher or AV receiver, you can try to connect it to the TV directly.
- in some TVs, some HDMI ports are different from others. You may switch to other HDMI port in the TV.
- whether HDMI source is chosen properly on the TV.
- whether you are using the bundled original power adapter.
- when you power on/off Chromecast Ultra, does the TV screen flash?
In some rare configurations, the TV may also give you a blank screen, for example:
- Your 4K TV supports HDCP 2.2;
- You are using the original power adapter;
- You are connecting Chromecast Ultra to an HDMI switcher (or receiver) which only supports HDMI 1.4.
If this is the case, you can use non-original USB power adapter to get 1080P streaming, not 4K. You will get a normal screen on the TV and it tells you that you are using a non-original adapter.
The solution for this situation is:
- to connect the Chromecast Ultra to the TV directly; or
- to get an HDMI switcher that supports HDCP 2.2.
Does HDMI cable matter for 4K streaming? Do I need an HDMI 2.0 cable?
The quality of HDMI cable does matter when streaming 4K contents, especially when streaming 4K HDR contents.
But technically there are only 4 types of HDMI cables:
- Standard speed HDMI cable without internet (category 1)
- Standard speed HDMI cable with internet over HDMI (category 1)
- High-speed HDMI cable without internet (category 2)
- High-speed HDMI cable with internet over HDMI (category 2)
When you use Chromecast Ultra to stream 4K contents, you do not need internet through HDMI. So, essentially, you are considering standard speed or high-speed HDMI cable.
For 4K contents, you need high-speed HDMI cable. Standard speed HDMI cable can only handle up to 1080i.
For high-speed HDMI cables, some vendors may tout HDMI 2.0 cable. In reality, there is NO standard or certification for HDMI 2.0 cable.
All high-speed HDMI cable should work with HDMI 2.0 and HDCP 2.2.
But if you think all high-speed HDMI cables are identical, then you are wrong.
The official high-speed HDMI (category 2) certification requires 10.3Gbps data rate (for 3 channels). This is sufficient for 4K contents. And high-speed HDMI cables were actually designed for contents from 1080p to 4K.
Some high-speed HDMI cables may have data rate up to 18Gbps. The vendors usually tout such cables as HDMI 2.0 cable. These cables are needed only for very rare situations.
Can I use an HDMI switcher when using Chromecast Ultra to stream 4K contents?
Yes, you can.
But you need to make sure both your TV and the HDMI switcher support HDCP 2.2.
I am streaming 4K contents, but it seems it is not 4K. Why?
Very likely, your connection speed is not fast enough.
Most streaming service providers will scale down the quality if your connection speed is not fast enough.
Please note, the speed referred here is the connection between the Chromecast Ultra and the service provider’s server. Speedtest normally only tests the maximum speed to your ISP. If the content provider’s server is not located in your region, the connection speed may be far slower than what you get in the speed test.
The solution to this connection speed issue is to use a wired connection to Chromecast Ultra.
The original power adapter for Chromecast Ultra includes an Ethernet port. You can connect it to your router with an Ethernet cable. The connection should be faster and more stable than the wireless connection.
Can you use Chromecast Ultra to stream 4K contents now?
If you have any questions or encounter any problems on using Chromecast Ultra to stream 4K contents, please let us know in the comment box below.
The community will try to help you find the solution.
For more Chromecast Audio guides, please visit Chromecast Audio guide page.
If your question is on Chromecast including both 1st generation Chromecast, and new Chromecast (aka Chromecast 2015), please visit Chromecast how-to guides page.