Connecting a Samsung Tablet to an HDMI Display over USB-C

Before you start

Connection over USB-C is local: the tablet sends video through the cable or adapter to the display. No cloud service, account sign-in or internet connection is required unless an app you are showing needs its own connection. The main requirement is a Samsung tablet whose USB-C port supports video output. Many Galaxy Tab S and recent Galaxy Tab A models support this, but support depends on the specific tablet generation and market version. If the tablet does not carry video over its USB-C port, a plain USB-C to HDMI cable or adapter will not work.

Use either a USB-C to HDMI cable with a single HDMI plug, or a multiport USB-C hub that includes an HDMI output. The adapter does not usually need its own power for basic mirroring, but a hub with power delivery can keep the tablet charged during longer sessions. Confirm that the HDMI cable and the display input work with another device before troubleshooting the tablet.

Step-by-step instructions

Start with the TV or monitor turned on and set to the HDMI input that matches the port you are using. Connect the HDMI cable from the adapter to that input, then connect the USB-C end to the tablet. The tablet may briefly show a notification or change its screen layout when the display is detected.

On a Samsung tablet, an external display is normally handled through the DeX interface. When DeX starts automatically, the external screen shows the taskbar and app windows while the tablet screen can remain usable or show the same DeX view depending on the selected mode. To change the behavior, open the DeX settings from the external display taskbar or from the tablet's DeX notification and choose screen mirroring if you want the display to show exactly what is on the tablet.

To start DeX manually when it does not open, open Settings, search for Samsung DeX or HDMI, and look for the display output options. Newer Samsung tablets may show an Auto start when HDMI is connected option. The exact wording changes between One UI versions, so use the search field inside Settings to find the available setting for your model.

Set the output resolution in the same display settings if the picture is not sharp. The tablet may offer an HD or full HD option, but the highest usable resolution depends on the adapter and display. Reversing a DeX or mirroring change is simple: disconnect the cable to return the tablet to its normal screen, or reselect the previous mode while connected.

Check the output

A successful connection shows the tablet's wallpaper, app windows or home screen on the external display. Move a window or open a video briefly and confirm that the display updates at the same time. If you set a specific resolution, check the image fills the display without large black borders; some borders can appear when the display shape does not match the tablet's output aspect ratio.

Audio may route to the HDMI device as soon as the display is connected. Play a short video and confirm where the sound comes from. The routing is controlled by the tablet's media output setting, while call or notification audio can behave differently depending on the One UI version.

Common problems and next steps

The display shows no signal

First confirm the monitor or TV is on the correct HDMI input. Some displays label ports differently, so try another HDMI port if available. If the adapter has power delivery, connect a USB-C charger to the adapter and check again. Finally, test the adapter and HDMI cable with another USB-C device that supports video output. A cable or adapter that works for charging only will not produce an HDMI picture.

DeX starts when you wanted mirroring

Open the display output settings while the adapter is connected and change the mode to screen mirroring. On some One UI versions the choice appears after tapping the display name or the DeX notification. If the external display still opens DeX automatically, turn off the auto-start option and reconnect the adapter.

The adapter charges the tablet but sends no video

Charging does not prove video support. The adapter must support HDMI output, and the tablet's USB-C port must carry DisplayPort or HDMI-alt mode video. Check the tablet model's specifications from Samsung for its display-output support if the adapter is known to work with another video-capable device.