ddcutil vs ExtLume
ddcutil
ddcutil.comExtLume
github.comSide by side
| Figure | ddcutil | ExtLume |
|---|---|---|
| Price from | Free | Free |
| Free plan | Yes | Yes |
| Free trial | — | — |
| Open source | — | — |
| Windows | — | Yes |
| Linux | Yes | — |
| API | Yes | — |
| Self-hosted | Yes | — |
| Plans published | 2 | 1 |
| Spec score · Monitor Control Software | 8.4 (#3) | 7.4 (#15) |
| Monitor controls | Its commands can detect monitors, report capabilities, read and set VCP feature values, and save or restore color related settings. | The app provides a separate slider for each safely identified active external display and shows its EDID model name. |
| Purpose | ddcutil is a Linux program for managing monitor settings such as brightness, color levels, and input source. | ExtLume is a Windows tray app for adjusting external monitor brightness when Windows provides a brightness slider only for the laptop panel. |
| Support | The project directs technical support questions, bug reports, and feature requests to its GitHub issue tracker. | The maker directs users to GitHub Issues for general troubleshooting and recommends including app, Windows, laptop or GPU, monitor, connection path, control mode, and expected-versus-actual result in compatibility reports. |
Plans
In their own words
ddcutil
ddcutil is a free Linux program for controlling monitor settings such as brightness, color levels and input source. It communicates with monitors through DDC/CI over I²C and supports monitors implementing MCCS over USB. Commands can find monitors, show capabilities, read or change VCP feature values, and save or restore color-related settings. The companion ddcui provides a Qt graphical interface with Summary, Capabilities and Features views, with the last allowing changes to modifiable values. For profile workflows, dumpvcp saves current settings to a file and loadvcp restores them. Developers can use the C API through libddcutil.so to read and write VCP values and handle profile-related features. The program is released under GNU GPL version 2. Setup requires the Linux kernel i2c-dev module, and non-root users need permissions to run it. It does not support laptop displays, which use a special API rather than I²C, and generally will not run in virtual machines because virtual video drivers do not implement I²C. For MCCS-over-USB table features, support is limited; the capabilities command synthesizes a response.
ExtLume
ExtLume is a Windows tray app for adjusting external-monitor brightness when Windows provides a brightness control only for the laptop panel. It offers a separate slider for each safely identified active external display and shows its EDID model name. When the monitor and the full cable or dock chain support DDC/CI, the app changes the physical backlight. If that is unavailable, it can use a click-through dimming overlay on a safely isolated external desktop area; this changes the image but not backlight power. ExtLume handles multiple displays, mirrored groups, hot-plugging, and resume, while excluding built-in panels and virtual displays. It targets Windows 10 and Windows 11 and requires .NET Framework 4.8. The free, MIT-licensed public beta is available from GitHub Releases as a per-user installer or portable ZIP and requires no administrator rights. ExtLume says it works offline without telemetry or network requests. It stores limited local monitor and dimming data, and its controls are limited to brightness rather than arbitrary VCP commands, resets, or automatic display substitution.