How Samsung DeX works

Overview

Samsung DeX is an extension of Android N's Multi-Window mode. Additional code development has also been included by Samsung that adds extras features and integrates it with Samsung hardware, such as the Iris scanner. There are no proprietary Samsung APIs needed to launch apps in Samsung DeX, as it is enabled by default. Apps typically run as long as they adhere to Androids best coding practices.

Figure 1: Overview of the different Samsung DeX Modes

Samsung DeX offers many different features to best suit your needs. Samsung DeX Mode allows your device to cast a PC-like experience to the big screen with the same apps you use on your phone every day. Finally, You can use DeX mode on your monitor while simultaneously using different apps on your device, or turn your device as an input device to control the DeX environment.

Samsung DeX device requirements

To run Samsung DeX, the following hardware and software requirements must be met.

  • Mobile Device: Samsung Galaxy S8, S8+, S9, S9+, and Note 8, Note 9, and Tab S4.

  • External Display: FHD (16:9 ratio) supported, HDMI display (Monitor, TV, Projector).

    • Samsung DeX with SEP v9.0 supports FHD(1920x1080, 16:9), HD+(1600x900, 16:9), and WQHD(2560x1440, 16:9).
  • Peripherals: DeX Station or DeX Pad, Samsung branded fast charger, mouse and keyboard (BT, USB or RF type).

    • Samsung DeX with SEP v9.0 can be used without a keyboard or mouse connection so users can utilize their phone’s touch screen or keyboard.
    • Samsung DeX, with SEP 9.5, now supports the Samsung multi port adapter or an HDMI adaptor for Note 9 and Tab S4 devices. While 3rd party HDMI adaptor are supported it is not recommended for optimal performance and quality.
  • OS: Android N onwards (API level 24 or above).

Phone Mode Samsung DeX with SEP v8.x Samsung DeX with SEP v9.x
Resolution WQHD FHD FHD, HD+, WQHD
DPI 640dpi (xxhdpi) 160 dpi (mdpi) 160 dpi (mdpi)
Orientation Portrait Landscape Landscape
Screen size xLarge xLarge
Peripherals N/A 1.Display connection required
2. Mouse required and keyboard recommended

  1. Display connection required
    2. Mouse and keyboard recommended

To check your current SEP version, go to Settings>About Phone> Software Information> Samsung Experience Version. In general, SEP is usually 1 version higher than your operating system version.

As shown in the screenshot below, a number of system configuration changes occur when a device switches from mobile to Samsung DeX mode. For more details on how to set up the configuration changes, see the section: Modifying your app.

Figure 2: Samsung mobile vs. Samsung DeX Mode

Setting up Samsung DeX

Samsung DeX station/pad

To switch into Samsung DeX using the station or pad, follow these steps:

  1. Connect the DeX Station to an external monitor using a HDMI cable.
  2. Connect the DeX Station to a power source using a Samsung branded fast charger (fast chargers have a lighting bolt symbol on them).
  3. Connect the keyboard and mouse to the mobile device through Bluetooth. Alternatively, connect the mouse and keyboard via USB.
  4. Place the mobile device on the DeX Station.

Samsung DeX HDMI adaptor

To switch into Samsung DeX using a HDMI adapter, follow these steps:

  1. Connect a Samsung Note 9 or Tab 4 to an external monitor using a HDMI to USB Type-C cable.
  2. Connect the keyboard and mouse to the mobile device through Bluetooth. Alternatively, connect the mouse and keyboard via USB dongle.

Figure 3: Mobile mode VS Desktop mode

Samsung DeX features

Samsung DeX introduces a number of new features to the Android experience. Some of these features include:

Category Feature


Basic app interaction

Interactive scroll bar
Contextual menu
Keyboard shortcuts
Mouse pointer
Horizontal navigation
Zoom in / out



Enhanced interaction

Drag & drop
Click & drag (selection)
Text selection (double-click)
New window
Mouse-over focus



Desktop Mode enhancements

Mouse and keyboard support
Re-sizable Multi-Window
Control bar buttons
Window active / inactive
Switch windows (Alt + Tab)
Enhanced notifications

Figure 4: Samsung DeX features

About Samsung DeX app optimization

Samsung DeX window types

When an app is launched in Samsung DeX, it adopts 1 of 3 different windows types:

  1. Resizable Window: Apps that comply with Android N Multi-Window standards. They operate in Free-Form Multi-Window Mode and can be re-sized according to need.

  2. Fixed-size Window: Apps that do not comply with Android N Multi-Window standards. They only operate in a fixed mobile dimension and cannot be re-sized.

  3. Not supported: Apps that are widget based only, or impractical to use in Samsung DeX. For example, Samsung Car mode. These apps do not work in Samsung DeX. Apps that also require finger-touch and restrict the use of a mouse do not work.

Figure 5: Differences in display modes