Displays

Noctalia Greeter uses its bundled wlroots compositor to configure displays. Put the settings on this page under [output] in /var/lib/noctalia-greeter/greeter.toml. On NixOS, use services.displayManager.noctalia-greeter.settings.output with the nixpkgs and project flake modules.

• Find connector names
• Choose which monitors show the greeter
• Arrange multiple monitors
• Match the desktop output mode
• Rotate an output
• Scale the interface
• Use automatic display settings with appearance sync
• Blank displays when idle
• Apply changes

Find connector names

Run this from a graphical Wayland session:

noctalia-greeter outputs --details

The first column is the connector name, such as DP-1 or HDMI-A-1. When the display exposes EDID identity data, the second column is a stable identifier made from its manufacturer, model, and serial number. Either value can be used for [output].name and for entries in layout, transforms, and scales. Per-output wallpaper entries continue to use connector names.

Choose which monitors show the greeter

By default, the greeter shows the same login interface on every connected monitor. Each display uses its own resolution and scale.

On laptops, the compositor follows the libinput lid switch. While the lid is closed and an external display can be enabled, internal eDP-* and LVDS-* outputs are disabled and removed from the greeter layout. They return when the lid opens or the last usable external display disappears. An explicit [output].name pin takes precedence over automatic lid handling.

To show it on only one monitor, pin that connector:

[output]
name = "DP-2"

If connector numbers change across boots, use the stable identifier shown by noctalia-greeter outputs --details instead:

[output]
name = "Acer Technologies XV242Y TL1EE0018521"

The compositor disables all other connectors at the KMS level while the greeter is running. A non-selected connector that is already disabled remains off without a temporary modeset. If name is empty, missing, invalid, or refers to a disconnected monitor, the greeter falls back to all connected outputs.

Arrange multiple monitors

Without an explicit layout, outputs are placed from left to right in connector name order. If that does not match the physical arrangement, set their logical positions:

[output]
layout = "DP-1:0,0; DP-2:2560,0"
scales = "DP-1:1; DP-2:1"

layout coordinates are logical pixels. Use matching per-output scales so the configured edges remain adjacent and the pointer can move naturally between monitors. Entries may use connector names or stable identifiers. Use semicolons between entries when identifiers contain spaces:

[output]
layout = "Dell Inc. DELL U2723QE ABC123:0,0; LG Electronics LG HDR 4K XYZ789:2560,0"
scales = "Dell Inc. DELL U2723QE ABC123:1.25; LG Electronics LG HDR 4K XYZ789:1.5"

When a configured layout entry has no matching scale, that output uses scale 1.0 to preserve its recorded logical coordinates. Connected outputs omitted from the layout are placed after the rightmost configured output and retain automatic DPI scaling. A global scale setting overrides all per-output scales.

Noctalia can copy layout, transform, and effective scale values from the desktop session through xdg-output. It records a layout only when multiple ready outputs report distinct positions; transforms and scales need at least one ready output. See Sync with Noctalia. Values declared in greeter.toml take precedence over synchronized values in sync.toml.

Match the desktop output mode

By default, the compositor uses each display’s complete EDID-preferred mode, including its refresh rate. This avoids selecting a higher advertised rate that a bandwidth-limited dock or MST link cannot drive.

Set both width and height to request a particular resolution:

[output]
name = "DP-2"
width = 5120
height = 2160
refresh_rate = 120

Both values are required and must be positive. A partial or invalid override is ignored. refresh_rate is in hertz and can be set with or without an explicit size. Without width and height, it applies to the EDID-preferred resolution. Nominal rates match fractional DRM modes within 1 Hz, so 120 matches modes such as 119.998. If the display does not advertise the requested size or a close refresh rate, the compositor logs a warning and falls back to the highest advertised refresh rate at the selected resolution.

For multiple displays with different refresh rates, use the mapping form of the same key:

[output]
refresh_rate = "DP-1:120; HDMI-A-1:60"

Entries are separated by semicolons and may use either connector names or the stable identifiers reported by noctalia-greeter outputs --details. Use either the numeric global form or the per-output mapping form, not both.

Note

width and height select the physical DRM mode in pixels, while refresh_rate selects refresh rates in hertz. It is separate from scale, which changes the size of the greeter interface. Mode dimensions are selected before any output rotation is applied.

Match the resolution and refresh rate to the desktop session to avoid an unnecessary mode change when logging in.

Rotate an output

For a portrait or flipped display, assign a transform to its connector:

[output]
transforms = "HDMI-A-1:270"

Available tokens are normal, 0, none, 90, 180, 270, flipped, flipped-90, flipped-180, and flipped-270. Separate multiple connectors with semicolons:

[output]
transforms = "DP-1:normal; HDMI-A-1:90"

Transform is independent of the physical mode size and UI scale. Noctalia can also synchronize transforms; see Sync with Noctalia.

Scale the interface

When no layout or scale override applies, the greeter calculates each output’s scale from its physical dimensions reported by EDID, falling back to its resolution. It uses the selected DRM mode size so cold boot and post-logout results match. Automatic scale is capped at 2.

Scale is resolved independently for each output in this order:

1. Global [output].scale in greeter.toml
2. A connector or stable-identifier entry in [output].scales from greeter.toml, then sync.toml when [output].use_synced_settings is true (the default)
3. Scale 1.0 when the output has a matching [output].layout entry but no scale
4. Automatic scale from display geometry

Set different scales per connector:

[output]
scales = "DP-1:1; DP-2:1.25"

Or force one scale on every output:

[output]
scale = 1.5

An invalid global scale, including a non-positive number, is ignored and resolution continues with the next applicable step above. The greeter lays out its interface at logical size and renders HiDPI buffers with Wayland fractional scaling.

These settings affect only the greeter session. They do not configure scaling inside the desktop session, although Noctalia Sync can copy the desktop’s effective per-output scales to keep synchronized layouts valid.

Use automatic display settings with appearance sync

If you connect different monitors to the same connector, or switch a monitor between resolution modes, a previously synced scale may no longer be suitable. To use the greeter’s display defaults while continuing to sync its appearance, set this in greeter.toml:

[output]
use_synced_settings = false

The option defaults to true. With false, the greeter ignores the synced layout, transforms, and scales in sync.toml. Output settings declared in greeter.toml still apply, including a pinned monitor, mode overrides, manual scales, and rotation.

For automatic layout and scaling, omit layout, scales, and scale from greeter.toml. Outputs are then arranged from left to right and scaled from their current display geometry. A declarative layout without a matching scale still uses scale 1.0, as described above; synced layout and scale are ignored together because the layout positions were recorded in logical pixels.

Sync continues to update appearance and store output metadata in sync.toml. The option controls whether the greeter uses that metadata, so it also applies to previously saved settings and later sync operations. Wallpaper and palette syncing continue normally. Restart greetd after changing the option.

Blank displays when idle

By default, the greeter never blanks the screen. To turn off active DRM outputs after a period without input, set [idle].timeout in seconds:

[idle]
timeout = 300

0 or an omitted key disables blanking. Valid values are 0 through 86400 (24 hours).

The greeter client keeps running while the outputs are blanked. A key press, mouse button press, or touch wakes them and restarts the idle timer. Pointer motion and scrolling wake an already blanked screen, but do not reset the timer while the screen is on. This prevents motion noise from a wireless mouse from keeping the greeter awake indefinitely.

NOCTALIA_GREETER_IDLE_TIMEOUT overrides the config value when set. Because greetd starts the greeter with an empty environment, add the variable to its session command with env:

[default_session]
command = "env NOCTALIA_GREETER_IDLE_TIMEOUT=300 /usr/bin/noctalia-greeter-session"

On NixOS with the nixpkgs and project flake modules:

services.displayManager.noctalia-greeter.settings = {
  idle.timeout = 300;
};

Both modules write the value to greeter.toml; neither adds the environment override to the greetd command. Restart greetd after changing the timeout as shown below.

Apply changes

Restart greetd after changing display settings:

sudo systemctl restart greetd

On runit:

sudo sv restart greetd