ScreenDimmer is a lightweight screen dimming application inspired by Nelson Pires' Dimmer application.

Pires' version works well, but has not been updated since 2012 and was missing some features that I needed for my HTPC. I wanted a solution to change the brightness on my HTPC late at night in a way that I could automate using my MCE remote control or by a schedule. Additionally, his version has some issues fully-covering the Windows taskbar, crashing when Windows shuts down, failing to gracefully handle issues with the settings file, etc. Using a ten-foot interface, these kinds of issues needed a fix.

  • Screen dimming by GDI API (adjusting the screen's gamma ramp), which affects everything equally, including the mouse cursor, popup context menus, full-screen applications, etc. Available from 5-50% dim.
  • Screen dimming by overlay (drawing a partially-transparent black area over the screen). Can be set to cover either the primary screen without taskbar, primary screen with taskbar, or all screens (and taskbars). Does not work in full-screen applications nor does it shade the mouse cursor, popup context menus, or other always-on-top windows. Available from 5-95% dim.
  • Global hotkeys to control dimming and toggle dim on/off. Win+Left Bracket or Win+Right Bracket (near the backspace key) control dim. Win+Ctrl+End will toggle the dim on/off.
  • Accepts control from other applications via Windows low-level SendMessage API. EventGhost can use this to automate control:
    Description Message wParam lParam lParam Values
    quit ScreenDimmer 921 (0x0399) 34701 (0x878D) 0 N/A
    change overlay color 921 (0x0399) 34702 (0x878E) RGB 0x00RRGGBB
    red/green/blue value
    adjust dim level 921 (0x0399) 34703 (0x878F) DIM % 0 - 100
    set dim effect on or off 921 (0x0399) 34704 (0x8790) STATE 0 = off, 1 = on
    set overlay-mode screen coverage 921 (0x0399) 34705 (0x8791) COVERAGE 0 = screen without taskbar,
    1 = screen with taskbar,
    2 = all screens
    set taskbar visible or hidden 921 (0x0399) 34706 (0x8792) STATE 0 = visible, 1 = hidden
    set mouse cursor visible or hidden 921 (0x0399) 34707 (0x8793) STATE 0 = visible, 1 = hidden
    lower dim by 5% 921 (0x0399) 34708 (0x8794) 0 N/A
    raise dim by 5% 921 (0x0399) 34709 (0x8795) 0 N/A
    toggle dim effect on or off 921 (0x0399) 34710 (0x8796) 0 N/A

Limitations On Use:
This download is freeware. All features of this program are available for all to use freely.

I maintain no liability or warranty for the use of this program in any situation.

Click here to download ScreenDimmer version 1.00 (842 KB) as setup installer.
Click here to download ScreenDimmer version 1.00 (207 KB) as portable (no install).