How to Keep a Window Always on Top on Mac

Pin a screenshot so that picture stays above your other Mac windows. macOS has no switch that floats every live window.

macOS does not give an ordinary window a switch that keeps it above every other app. What you can keep on top is a picture of the window: a Shoverlay pin. The image floats above the apps you are using.

Pin the picture

Capture the window, the diagram, or the ticket you need to see.
Choose pin on Quick Access.
Move it beside your work. Resize it. Close it when the reference is finished.

Rounded corners, a shadow, or a border, in Advanced settings, make the pin easier to distinguish from the real window underneath.

When the thing you need is the live app

Pin does not keep the app itself hovering over everything. If a live window should stay in place while other windows move around it, that is Pin Mode in Gablet.It holds the window and reflows the others. It is not a floating layer.

Install Shoverlay on the Mac App Store.