Brightness

Brightness control uses the kernel backlight interface by default. ddcutil support is opt-in for external monitors that expose DDC/CI brightness.

[brightness]enable_ddcutil = falseignore_mmids = [] # e.g. ["ACI-ROG_PG279Q-10220"] - skip in all ddcutil commandsminimum_brightness = 0.0 # never let brightness drop below this floor (0.0 to 1.0)sync_all_monitors = false # if set to true, makes every display have the same brightness
[brightness.monitor.eDP-1]backend = "backlight" # auto | none | backlight | ddcutil
[brightness.monitor.DP-1]backend = "ddcutil"

Notes:

enable_ddcutil = true only enables DDC/CI discovery - it does not force every monitor to ddcutil.
ignore_mmids passes --ignore-mmid to every ddcutil invocation. Run ddcutil --verbose detect to find monitor model id strings.
minimum_brightness is an opt-in floor (default 0.0 = disabled). Any brightness change is clamped to at least this value, and the control center slider cannot go below it - useful to keep the screen from going completely dark.
sync_all_monitors only syncs the brightnesses when one of the display brightnesses change, it does not actively sync them every now and then
Per-monitor overrides use the same connector/description matching rules as bar monitor overrides.
backend = "auto" prefers kernel backlight when available and falls back to ddcutil.
backend = "none" hides brightness control for the matched monitor.
ddcutil is treated as best-effort - repeated DDC failures cool down that monitor to avoid hammering the bus.

Section titled “Related IPC”

For brightness commands, targets, accepted value formats, and OSD behavior, see System Controls → Brightness.