How to Keep a Window Always on Top on Mac

Keep a reference on top of your other Mac windows by pinning a screenshot above them, or hold one live window in place while you arrange the rest.

macOS does not give every window a switch that says “keep this on top.” People still need a reference that does not disappear under the next app they click. There are two different jobs, and they use two different tools.

Keep a picture on top of other windows

If the thing you need on top is an image — a design, a ticket, a diagram, a list — pin the screenshot. In Shoverlay, take the shot or reopen it from History, then choose pin on Quick Access. The image floats above other apps. Drag it, resize it, and close it when you are done. Advanced settings can add rounded corners, a shadow, or a border so you can tell the pin apart from the window underneath.

That is the way to keep a captured window on top while you work in a live app. Install Shoverlay on the Mac App Store. The capture stays on your Mac.

Keep a live window from being shoved aside

If the thing you need is the app itself, not a picture of it, use Pin Mode in Gablet. Pin Mode holds that window and reflows the others around it. A spec, a call, or a chat stays where you put it while you throw and snap the rest of the desk. It is not a floating layer painted over every other app. It is a window that stays put inside the layout.

You can download Gablet. macOS 11.5 or later. The download includes a 7-day free trial, then a paid license.
Grant Accessibility in System Settings → Privacy & Security → Accessibility, then quit and reopen Gablet.
Turn on Pin Mode in Settings. Pin the window that should stay. Arrange the others around it.

Which one answers “keep a window on top”

The reference is a screenshot — pin it in Shoverlay. It stays above the apps you are using.
The reference is a live window that must not move while you rearrange the desk — Pin Mode in Gablet.
The window should leave the screen entirely — that is Stash, not a pin.