What on Earth is DP Alt Mode and why is My Phone not supporting it?

What on Earth is DP Alt Mode and why is My Phone not supporting it?


You have been waiting for the day you will finally get to connect your phone to your TV and watch those your shot moments beautiful wedding videos and pictures over & over again. With this in mind, you knew you had to buy a USB C to HDMI cable and you did. However, after getting yourself a glass of milk & some cookies to enjoy your video with, you went straight to the TV to connect your phone to it, but the videos wouldn't show. If you have ever been in a similar situation, you would agree with me that it is a very annoying one.

You tried all you could to the point of even rebooting your phone, all to no avail. Angrily, the next day, you went back to the HDMI adapter manufacturer and said, they sold you a bad HDMI cable. The staff replied and said, Sir, the problem would be that your phone does not support DP Alt Mode. Then you asked, what on earth is DP Alt Mode and why does my phone not support USB C to HDMI?

What is DP Alt Mode

DP Alt Mode simply means DisplayPort Alternate Mode and this feature enables the transmission of video signals through a USB C cable. Moving forward, it is important you know that the new USB C connector was developed to support Alt Mode features which allow both USB & non USB transmissions. However, not all manufacturers create their Type C USB connectors to support Alt Mode.

In other words, there are about 5 available functional alt modes capabilities. They are DisplayPort Alt Mode, ThunderBolt Alt Mode, VisualLink Alt Mode, HDMI Alt Mode, and MHL Alt mode. And it is possible your device Type C connector was not manufactured to support Alt Modes data transferring features. Hence, transmitting video signals from your device through the HDMI cable (HDMI Alt mode) will not be possible.

Are you still confused? Do not be. In simple terms transfer of media, and data is usually through USB to USB medium (2 compatible media). Therefore, seeing that an HDMI cable is required to transmit media (video, audio) data onto a larger screen, alt modes capabilities were activated in Type C connectors to enable them to work with HDMI cables and display your videos on a larger screen. But the sad news is, that not all type C connectors support this.

How to check if my device's connector supports DP Alt Mode?

Furthermore, having understood that not all devices with Type C connector support DP Alt Mode, it is good to be sure that your device support DP Alt Mode before purchasing a USB C to HDMI cable. You might be asking how would you know this. It's quite simple. All you need to do is check. Highlighted below are the various ways you can check if your device is DP Alt Mode compatible or not.

1. Check with your phone/laptop/tablet manufacturer support

Here is the first thing you can do, go to your device manufacturer support page on Google and simply ask on the forum if the model of your device supports DP Alt Mode. Better still, you could get through to your device manufacturer's customer care line and put a call through to them or chat up a customer care representative.

2. Google the user manual of your device.

In addition, another thing you can do to check the DP Alt Mode compatibility of your device is to check the user manual. There are devices that come with user manual instructions under settings. You can also Google your device's user manual. In the manual, you can check the description of the connector spec or the part of connecting a display to your device. For Mac users, in your user manual, go to charging and expansion, if your device is DP Alt mode compatible, you will see it listed there.

3. Share the needed information

Now that you know that your device might not be compatible with a USB C to HDMI cable due to the lack of alt mode features configuration, before purchasing your HDMI adapter, share the specific model number of your device with the adapter manufacturer. This way, they can be certain that the HDMI adapter you are purchasing will work with your device. Or they can help troubleshoot and find ways to enable DP Alt Mode on your device if possible.

List of Devices that are DP Alt Mode Compatible (not complete)

Here are some devices that support DP Alt Mode:

  • Almost all types of MacBook Pro/Airwith Thunderbolt port;
  • iPad Pro/Air 2020 and later;
  • Samsung S10 & later smartphones;
  • Huawei P20 and recent models;
  • Dell XPS 13/15;
  • Lenovo laptops with Thunderbolt port, etc.

Some DP Alt Mode non-compatible devices are:

  • Xiaomi and Redmi Phones;
  • Poco, Oppo, Vivophones;
  • Samsung A series like A52/A23;
  • Acer laptop An515-54;
  • HP Pavilion - 15t-cs300 CTO;
  • HP 15-dy1027od, etc;


With the explanation given so far, we can conclude that it is possible that your devices might not be able to stream video onto your TV or other larger screens via a USB C to HDMI cable adapter. Luckily, device manufacturers have implemented wireless screen mirroring on such phones or tablets. However, if you still want to connect your device to a TV or monitor via HDMI connection, there are ways around it. Feel free to check out how to enable the HDMI connection for a phone that does not support DP Alt Mode.


Author: Yuusuf Oluwaseun Adetona

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