Dark

Dark is a straightforward piece of software you can use to seamlessly send your monitor to sleep by just double-clicking an icon from the taskbar notifications area.
It comes in handy whenever you want to temporarily leave your computer unattended, without going through the trouble of locating and activating the built-in power management features just to be able to take a brief break from work.

Setup, prerequisites, and systray integration

The downloaded installation kit gets unpacked quickly and with minimum effort on your behalf. On the other hand, because it was developed using Microsoft's software framework, you must download and install .NET Framework unless you already have it. Modern Windows iterations have it integrated, so you shouldn't experience issues in this regard.
Once fired up, Dark gets integrated into the taskbar notifications area, although its presence isn't indicated through visual or audio means. You can send the monitor to sleep by just double-clicking the systray icon.

Effortlessly switch the monitor to sleep mode

The task is carried out immediately, without delay, and it doesn't affect any running applications, so there's no risk of losing unsaved work. The monitor can be woken up by just moving the mouse, clicking a button or hitting a key.
Additionally, the small-sized software application integrates an option into the right-click menu of the tray icon, which sends it to the Windows startup sequence. Therefore, it gets launched by default every time you turn on your computer, until disabling this setting.

Evaluation and conclusion

Unsurprisingly from such a compact software product, Dark didn't put a strain on the PC's performance in our tests. It was undemanding regarding RAM and CPU usage. Furthermore, it stayed stable throughout our evaluation, without affecting other running utilities.
To sum it up, Dark may not be sophisticated, but it delivers a simple and efficient solution for quickly turning your monitor black by entering sleep mode.