Change the brightness of your external monitors from the Windows tray, instead of reaching for the buttons on the monitor itself.
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Windows has no built-in way to control the brightness of an external monitor. The slider in Settings only moves a laptop's internal panel; for everything plugged in over HDMI or DisplayPort you are left poking at the physical buttons on the bezel.
Glow puts a slider in your system tray that changes the brightness in the monitor itself, over the DDC/CI protocol the monitor already speaks — not a dark layer drawn on top of the picture. Every connected display gets its own slider, plus a per-screen night mode for warmer colours in the evening.
It is a single self-contained .exe, uses essentially no CPU while idle, and is free and open source. If you came here looking for a replacement for ClickMonitorDDC, which has not been updated in years, or for an alternative to Twinkle Tray or Monitorian, that is exactly the job Glow does.
- Download
Glow-Setup-x.y.z.exefrom the latest release. - Run it and tick Start Glow automatically when Windows starts.
- Glow appears in your tray. That's it.
Prefer not to install anything? Grab Glow-x.y.z-portable.exe from the same release and run it directly — it is fully self-contained and leaves nothing behind.
You need: Windows 10 or 11 (64-bit) and a monitor that supports DDC/CI — most external desktop monitors do. See Not working? if no brightness slider shows up.
Click the Glow icon in the system tray (next to the volume icon) → a popup appears with an All monitors card that drives every screen at once. Press Each monitor separately to unfold a card per display, and again to fold them away; the popup remembers which way you left it.
Every card has a sun row (hardware brightness over DDC/CI) and a moon row (night mode). The master sliders keep the value you set them to — adjusting one screen on its own never drags them along, so the master stays something you aim rather than a running average. Its night pill reads Mixed when your screens disagree.
Right-click the icon for Night mode on all monitors, Run at startup and Exit. Middle-click toggles night mode everywhere without opening the popup.
- True hardware brightness — drives external monitors over DDC/CI (
Dxva2.dll), not a software overlay. The monitor's own backlight actually changes, so you get the power saving and the eye comfort, not a dimmed image. - Multi-monitor — auto-detects every connected display and shows a separate slider for each, labelled with the real model name (read from EDID).
- Per-monitor night mode — each screen gets its own warmth, or warm them all at once from the All monitors card. Works even on displays with no DDC/CI, because it goes through gamma ramps rather than the monitor's own colour controls.
- Settings that stick — night mode is saved against each display's EDID identity, so it survives a reboot and follows the monitor to another port. Re-applied automatically after sleep, a resolution change or unlocking, where Windows would otherwise reset it silently.
- Near-zero footprint — no background timers or polling; the app sleeps in the message loop and only wakes on a click. Idle CPU ≈ 0%.
- Single self-contained
.exe— no .NET runtime to install. - Auto localization — UI follows the Windows display language (English / Русский), English fallback.
- Matches your theme — follows the Windows light/dark app theme and accent colour, with Windows 11 rounded corners.
- Silent autostart — optional launch with Windows via
HKCU\…\Run. - Auto-update — checks GitHub Releases and updates once you say yes. Betas are skipped.
- Clean uninstall — removes the app, the autostart key and all config; leaves no trace.
A monitor has no brightness slider, only night mode. That display does not expose DDC/CI. Two common causes: it is a laptop's internal panel — most of them genuinely do not support it — or DDC/CI is switched off in the monitor's own on-screen menu, where it is often buried under Settings, Others or OSD. Turn it on there and restart Glow. Displays without DDC/CI still get a card, with night mode only.
Night mode turns itself off, or fights with Windows. Night mode drives display gamma, which is the same knob the Windows Night light feature uses — whichever wrote last wins. If you use Glow's, switch the Windows one off in Settings → System → Display.
Night mode does nothing on one screen. That screen is probably running in HDR mode, which ignores gamma ramps entirely. Turn HDR off for that display if you want night mode on it.
Brightness resets after sleep or a resolution change. It should not — Glow re-applies your settings after sleep, unlocking and display changes. If it still happens on your hardware, please open an issue with your monitor model.
Anything else, or something behaving oddly? Open an issue — questions are welcome, not just bug reports.
Versions tagged -beta are published as GitHub prereleases and have to be downloaded from the releases page directly — the latest release link above always points at the newest stable build.
Beta builds never check for updates on their own, so they won't nag you mid-test; Check for updates in the tray menu still works when you ask for it. Stable installs are never offered a beta either, because the update check only looks at the latest stable release.
Bug reports, monitor compatibility notes and pull requests are all welcome — see CONTRIBUTING.md for the tech stack, how to build from source and how releases are cut.