Samsung phones with DeX support carry a built-in interface where the phone behaves like a computer. A few parameters change so the experience resembles a desktop operating system — but it never stops being Android, and nothing about your phone's configuration is touched.
What it is, in practice
DeX is a mode that ships with many Galaxy models. When you connect the phone to a TV or monitor, instead of simply mirroring the phone's screen, it opens a home screen designed for bigger displays: windows, a taskbar, everything you'd expect from a desktop — within the natural limits of an Android smartphone. The phone becomes the "brain", and the monitor becomes the workspace.
Just add a mouse and a keyboard.
It's not screen mirroring
Screen mirroring shows on the monitor exactly what's on the phone. This is different — DeX reorganizes the phone's elements so it works like a computer, while the phone-mode setup stays untouched underneath.
How you turn it on
There are two ways:
- With a cable: a USB-C to HDMI cable or adapter plugs the phone straight into the monitor's HDMI port. It's the most stable option.
- Wireless: on newer compatible TVs, you can connect over Wi-Fi, no cable at all.
How long it's been around
DeX isn't new to Samsung phones: it launched in 2017 with the Galaxy S8, and it's been refined ever since — it's still there on the S26 Ultra.
Why this matters
An older Galaxy that wouldn't fetch much in a trade-in still has a processor, Wi-Fi and a working screen. Plugged into a TV with DeX, it can become genuinely useful again — closer to a streaming box than to a drawer relic. In the next note in the series, I go through which Galaxy models support it — so you can find out if yours does. This note is part of the Samsung DeX complete guide.