Snap a Mac window to the screen edge or a size you draw

Drag a window to an edge, or to an area you set up, when a half-screen split is not the layout you want.

Edge snapping is the habit of dragging a window until it occupies a region. Gablet does that, and it also lets you draw regions when the built-in halves are the wrong shape.

Snap to an edge

Drag a window to the edge of the screen. Gablet drops it into the matching area. This is the motion to use when your hand is already on the window and you do not want a shortcut.

Draw an area

Halves and quarters fail when a sidebar should be narrow and the document should take the rest. Draw the areas you actually use, with the sizes and positions you want. Drag a window into one of those areas the same way you would drag it to an edge.

If nothing snaps

Gablet needs Accessibility permission to move windows. Turn it on in System Settings → Privacy & Security → Accessibility, then quit and reopen the app. macOS 11.5 or later. You can download Gablet. The 7-day trial comes first, then a paid license. Gablet does not track usage.