This guide covers everything you can do with individual displays in Dimly: brightness, sleep, wake, and blackout.
Click the Dimly icon in the menu bar. The panel shows a tile for each connected display. Click a tile to expand it and reveal the controls.
You can also open the panel with a global hotkey. The default is Cmd + Ctrl + Option + M. You can change this in Settings → Shortcuts.
Drag the Brightness slider to set the level for that display. Use the − and + buttons for fine-grained adjustments.
Brightness works differently depending on what your monitor supports:
- DDC supported (green badge) - Dimly sends the brightness value directly to the monitor's hardware. The monitor's physical brightness changes, just as if you used its on-screen menu.
- Overlay mode (blue badge) - Dimly draws a transparent dimming layer over the screen. The image is visually darkened without touching monitor hardware. Fully functional, just software-based.
Dimly always tries DDC first. If the monitor doesn't support it, overlay mode kicks in automatically. You don't need to configure anything - it just works.
Sleep sends the monitor into standby - it turns the panel off and stops drawing power, just like closing a laptop lid.
- If DDC is supported, Dimly sends a hardware standby command. The monitor powers down completely.
- If DDC is not supported, Dimly shows a full-screen blackout overlay as a visual substitute. The monitor stays on electronically but the screen goes black.
Wake reverses a sleep or blackout state. Use the Wake Externals button in Quick Actions to bring all external displays back at once, or wake a single display from its tile.
Emergency recovery: If you accidentally black out or sleep all your displays, press the panic hotkey Ctrl + Option + Shift + P to restore everything instantly.
Blackout draws a full-screen black overlay on a display. It's immediate and works on every monitor regardless of DDC support.
Use blackout when you want to:
- Block glare from an unused screen without putting it to sleep
- Quickly hide a display during a meeting or presentation
- Darken a display while keeping it powered on and ready
To toggle blackout on all external displays at once, Option-click the Dimly menu bar icon. To toggle a single display, expand its tile and use the Blackout Display / Restore Display button.
Blackout vs. Sleep:
- Blackout is instant, software-only, and always available. The monitor stays on.
- Sleep (with DDC) fully powers down the panel. Takes a second or two for the monitor to respond.
The Quick Actions section at the top of the panel has one-tap buttons for common actions:
| Button | What it does |
|---|---|
| Toggle External Blackout | Blackout or restore all external displays |
| Sleep Externals | Send all external displays to sleep |
| Wake Externals | Wake all external displays |
| Panic: All On | Restore every display immediately |
| Show Display Numbers | Show numbered overlays on each screen |
Show Display Numbers puts a large number on each screen so you can quickly identify which display is which when renaming or rearranging.
Open a display tile to see its controls. From the tile you can:
- Set Brightness with the slider
- Put the display in Standby or Wake it
- Toggle Blackout on or off
- Rename the display (give it a friendly name like "Left Monitor")
- Copy the display's hardware ID to the clipboard
Right-click or use the tile's context menu for Rename Display and Copy Display ID.
If you want a display to always use overlay mode - even when DDC is available - enable Overlay Only (Never Sleep) in Settings → Displays for that monitor. This is useful when:
- A monitor's DDC sleep/wake is unreliable or slow
- You prefer instant blackout behavior over hardware standby
- You're using a monitor where DDC wake is inconsistent
Each display tile shows its current control mode:
| Badge | Meaning |
|---|---|
| DDC (green) | Hardware control is active |
| Checking DDC (orange) | Dimly is probing - normal for a few seconds after connecting or waking |
| Overlay mode (blue) | DDC unavailable; software control is in use |
If a display stays on Overlay mode and you expected DDC, see the Troubleshooting guide.
Long model strings like "DELL U2723QE" can be hard to tell apart in a multi-monitor setup. Use Rename Display to give each monitor a friendly name. The name persists across reconnects and is used everywhere in Dimly's interface.
To rename: expand the display tile → right-click or open the menu → Rename Display.
By default, the internal display (your MacBook screen) appears separately. Enable Merge internal and external monitor order in Settings → General to arrange all displays - built-in and external - in one shared list. This lets you set a custom viewing order that matches your physical desk layout.