Glass mode is an effect that is similar to Opacity, but unlike Opacity, this effect is more advanced and allows you to adjust a different opacity for each layer. The window is divided into three main layers (using an image detection algorithm):

• Background – anything in the window that is not text or image. These pixels are blank content (e.g., white background around text)
• Texts – any text on the window. This also includes any shapes.
• Images

For each layer, you can set the opacity level.

Note: This feature is experimental and unstable

The following video demonstrates what kind of scenario this feature may be useful.
This video was recorded before WindowTop was rewritten in C# so you will notice an old-looking toolbar. But the algorithm is a C++ code, and it is the same until today

The use case that is shown is when you do web programming. In this use case, you can see the website behind on the same monitor while editing.

You may think that this is like opacity. But this is not exactly true. It is similar but not the same.
This effect is much more complicated and can set a specific transparency level to the background pixels while keeping the text without transparency.

Enabling the Glass () button and hotkey

By default, the glass mode button is not shown on the toolbar, and no hotkey is assigned.
To enable it in the toolbar and assign hotkey: