How can I restore monitor brightness after it resets during sleep?

If your monitor's hardware brightness is controlled through DDC, enable Reapply DDC settings on wake. BetterDisplay can resend its stored DDC settings after wake even when the app's displayed percentage has not changed.

Open Settings > Displays > [display] > Device Control > DDC Control > Advanced…, then enable the wake option. Set your preferred brightness before sleeping the Mac. The option reapplies DDC settings, so review other DDC controls you use as well.

If manual adjustment works after the monitor wakes, BetterDisplay may be sending the wake command too early. Note the current additional delay, increase it and test again. More general wake delays are available under Settings > Application > Advanced Settings & Privacy… and affect the app broadly. Change one relevant setting at a time. Delays help only when the command already works after the monitor is ready.

The same readiness issue can affect a CLI command run by a wake script, including hardware contrast. First run the script after the display has fully woken. If it works then, add a delay before the wake-triggered command and verify the monitor’s actual setting. Check the monitor’s own setting, because the app’s value can change even if the monitor misses the command.

For a monitor that forgets its settings when physically unplugged, DDC values on startup > Write last used values to display in the same advanced settings can replay saved ranged/on/off adjustments when BetterDisplay sets up its DDC controller again after reconnection. Review all saved adjustments, including safe volume/mute values, before trying it. This applies after reconnection. Reapply DDC settings on wake applies after sleep. Saved-value restoration does not run command-only actions such as input switching, power commands or factory reset. The shared startup/wake restoration policy can also prevent these restores.

If a newly connected monitor is not ready to receive commands, record Configuration delay under Settings > Application > Advanced Settings & Privacy… before considering a change, then reconnect and check the monitor’s actual setting. This delay affects all displays, so check the result on each one.

If DDC Control is unavailable, check which controller provides brightness. Use that controller’s settings instead.

Compare the monitor's own brightness setting with the app's value. If the monitor’s hardware level is unchanged but the image becomes dim, check software brightness, HDR and the active color configuration. See DDC settings and DDC readback.

For a diagnostic workflow that separates saved identity, mode protection and monitor adjustments, follow Restore brightness and display settings reliably after wake.