Deskbridge › Guides › DeX with scrcpy

Run Samsung DeX on your Mac with scrcpy (free, command line)

Install scrcpy with Homebrew, turn on USB debugging, plug in your Galaxy and run scrcpy --new-display=1920x1080/160. On phones with One UI 8 or later, DeX starts on that virtual display and opens in a Mac window. The rest of this guide covers sharp sizes, portrait mode, shortcuts and the two gotchas — sleep and the lock screen — that confuse almost everyone.

Updated October 21, 2026 · Every command tested on a Galaxy Z Fold 7 (One UI 9) with scrcpy 5.0.1 on macOS

Why this works

scrcpy (by Genymobile) streams an Android display to your computer and sends your keyboard and mouse back. Since version 3.0 it can create a brand-new virtual display with --new-display. Starting with One UI 8, a Galaxy phone launches the full DeX desktop on any new virtual display — so scrcpy gives you the real DeX, not a mirror of your phone screen. (Background: how DeX on a Mac works in 2026.)

1. Install scrcpy and adb

brew install scrcpy
scrcpy --version          # must be 3.0 or newer for --new-display

Homebrew's scrcpy pulls in adb (Android's debug bridge) automatically. If adb isn't found, also run brew install --cask android-platform-tools.

2. Turn on USB debugging and authorize your Mac

1. Phone: Settings › About phone › Software information, tap Build number seven times.
2. Settings › Developer options: turn on USB debugging.
3. Plug in, then on the phone tick Always allow from this computer and tap Allow.
4. Check it on the Mac:

   adb devices
   # List of devices attached
   # RFXXXXXXXXX    device        ← "unauthorized" means tap Allow on the phone

3. Start DeX

scrcpy --new-display=1920x1080/160

A window opens with the DeX desktop. The format is WIDTHxHEIGHT/DPI.

Get the size and DPI right

If DeX looks blurry, enormous or microscopic, the DPI doesn't match the resolution. The rule we use: DPI = 160 × width ÷ 1920. That keeps a comfortable “1080p-sized” desktop at any resolution, just sharper.

Keep width and height multiples of 8 — video encoders dislike odd sizes, and most phones top out around 4K.

Portrait without the cramped tablet layout

Simply swapping width and height at the landscape DPI makes the display about 1,080 dp wide, so apps like Messages switch to their two-pane tablet layout. For a portrait window that behaves like a big phone, size the DPI to the short edge: DPI = 160 × short edge ÷ 480 (about 480 dp wide). For 1080×1920 that's 360; for 2160×3840 it's 720.

4. A better everyday command

scrcpy --new-display=3840x2160/320 \
  --window-title=DeX \
  --stay-awake \
  --video-codec=h265 \
  --max-fps=60 \
  --shortcut-mod=lsuper,rsuper

• --stay-awake keeps the phone awake while it's plugged in — important, see below.
• --video-codec=h265 looks better at the same bitrate; drop back to h264 if scrcpy exits immediately.
• --shortcut-mod=lsuper,rsuper makes ⌘ the shortcut key. (scrcpy calls the Command key lsuper/rsuper; lcmd is not valid.)

Useful shortcuts with that setting: ⌘H home, ⌘B back (or right-click), ⌘S recent apps, ⌘N notifications, ⌘F fullscreen. Phone audio plays on the Mac by default on Android 11+, and you can drag files onto the window to send them to the phone's Downloads.

5. The two gotchas: sleep and the lock screen

A sleeping phone freezes DeX

When a Galaxy phone sleeps (dozes), the DeX display stops responding. That happens when you press the power button — and, surprisingly, with scrcpy's own --turn-screen-off, which sends Samsung phones into doze. Don't use --turn-screen-off for DeX. If the phone does sleep, wake its own display from the Mac:

adb shell input -d 0 keyevent KEYCODE_WAKEUP

The -d 0 matters: on Android 14+ each display group sleeps separately, so a plain wake key goes to the focused DeX display and the phone screen stays dark.

A locked phone hides the dock

DeX keeps running behind the lock screen, but Samsung shrinks the dock to bare navigation buttons — no apps, no clock — and blocks typing until you unlock. It's a security rule, not a bug. Unlock the phone (fingerprint works without opening a foldable) and everything returns. More on this in keeping the phone screen off without freezing DeX.

6. Wireless (optional)

# Phone: Settings › Developer options › Wireless debugging › Pair device with pairing code
adb pair 192.168.1.20:37155        # IP:port and code from the pairing screen
adb connect 192.168.1.20:41623     # IP:port shown on the main Wireless debugging screen
scrcpy --new-display=1920x1080/160

Over Wi-Fi --stay-awake has no effect (the phone isn't charging from the Mac), so keep the phone from sleeping another way.

Or let Deskbridge do all of this

Deskbridge wraps exactly this setup in a Mac menu-bar app: it bundles scrcpy and adb, opens DeX the moment you plug in, picks the sharp size for your screen, switches to phone-style portrait in one click, and keeps the phone screen black without freezing DeX (Secure Blackout). It also unlocks your phone from your Mac keyboard and adds call banners, notifications and apps in their own windows. $12 once after a 3-day trial — or stick with the commands above; they're free and they work.