How can I tell if I am running Wayland?

Question

Wayland is the default display server for Ubuntu 17.10 "on supported systems". But how can I tell if my platform is supported and I'm actually using Wayland?

Answer 1

Open the terminal and type in:

echo $XDG_SESSION_TYPE

Check if it prints wayland.

Answer 2

You could install mesa-utils-extra and run es2gears_wayland If the app runs, you are running Wayland.

For a fun way to check whether a specific app is using Wayland or XWayland, run xeyes. The eyes will move if the cursor is over an X or XWayland window.

Or run this in a terminal:

env | grep -i wayland

If there is no output, you are not running Wayland.

Answer 3

Use that command in the Ubuntu terminal:

echo $DESKTOP_SESSION

Look at the value returned. If on wayland it will return

gnome-wayland

ubuntu-wayland  #  Ubuntu 20.10  

Answer 4

Settings > About > Windowing System

On Ubuntu 21.04, you can also see it from the Settings GUI (Win key, type Settings, select. Executable name: gnome-control-center), which is nice.

The default is Wayland on that system, 21.04 appears to be the first release where it was the default: https://www.omgubuntu.co.uk/2021/01/ubuntu-21-04-will-use-wayland-by-default

If I change to X11 as mentioned at: How do you switch from Wayland back to Xorg in Ubuntu 17.10? it says:

Windowing System: X11

instead.

As mentioned at: Ubuntu 21.04: how to enable Wayland? however, if Ubuntu detects that you don't have the hardware support, it fallbacks to X11 by default.

Also, the NVIDIA 460 driver doesn't support Wayland, and X11 becomes your only choice once you install it.

BTW, the 21.04 minimal ISO install (which has Wayland and no NVIDIA driver, which is proprietary and needs to be installed manually later) has a known bug that crashed my UI every other day: Ubuntu UI screen image freezes randomly during usage after fresh 21.04 install, suspecting Wayland or Nouveau making it unusable. The problem stopped when I installed the nvidia driver and used X11.

Answer 5

I don't know if this answer generalizes, but I found that running xrandr will show different monitor names if running wayland vs. not:

xrandr --listmonitors
# On Ubuntu: 0: +*eDP-1 4384/344x2466/193+3840+0  eDP-1

# On Ubuntu-wayland: 0: +XWAYLAND0 1920/340x1080/190+0+0  XWAYLAND0

Answer 6

If you execute echo $WAYLAND_DISPLAY, a text (like wayland-0) will be printed only under Wayland.