5 Window Resizing Tricks Every Mac User Should Know

Everyone knows you can drag a window's edge. Almost nobody knows what happens when you hold Option or Shift while you do it, or that double-clicking an edge does something at all. Five tricks, all built into macOS 13 through 15, no settings required for the first four.

1. Option-drag: resize both sides at once

Hold Option while dragging any window edge, and the opposite edge moves too — the window grows or shrinks symmetrically around its center. Drag the right edge outward with Option held and the left edge mirrors it. It also works on corners: Option-drag a corner and all four sides resize around the center point. This is the fastest way to make a centered window bigger while keeping it centered.

2. Double-click an edge: snap it to the screen

Double-click any window edge and that side of the window flies to the corresponding edge of the screen. Double-click the bottom edge and the window extends to the bottom of the display; double-click the left edge and it reaches the left edge of the screen. It's "maximize in one direction" — perfect for making a document window full-height without touching its width. (Add Option to the double-click and both opposing sides expand.)

3. Shift-drag: keep the proportions

Hold Shift while dragging a corner and the window scales proportionally, keeping its aspect ratio. Combine the modifiers — Shift + Option — and it scales proportionally around its center. Niche, but exactly right when you've carefully shaped a video or preview window and want it bigger without changing its shape.

4. Double-click the title bar to zoom

Double-clicking a window's title bar triggers whatever System Settings → Desktop & Dock → Double-click a window's title bar to is set to. Set it to Zoom and the double-click toggles the window between its current size and the size the app considers ideal — usually filling the screen — without entering full screen. The same zoom lives on Option + click on the green traffic-light button, and in the menu bar under Window → Zoom. If yours is set to Minimize and you keep losing windows into the Dock, this setting is why.

5. Use the Window menu for precision moves

The Window menu has always had Zoom and Center-style commands, and on macOS 15 Sequoia it grew a full Move & Resize submenu: halves, quarters, Fill, Center, and Return to Previous Size to undo any of them. The halves and Fill have shortcuts (fn + Ctrl + arrows, fn + Ctrl + F), which means on Sequoia you can do most day-to-day resizing without the pointer at all. On Ventura and Sonoma, hovering the green button offers full screen and Split View placements instead.

Bonus habits that make resizing rarer

• macOS remembers window sizes per app — shape a window well once, and it generally reopens that way.
• The grab zone is bigger than the visible edge — you don't need pixel-perfect aim; the resize cursor appears a few points around every border.
• Resizing works from any edge or corner — a habit worth breaking is dragging everything from the bottom-right like it's 2009.
• The modifiers combine with everything above — Option works with the double-click trick, Shift works with corner drags, and all of it works in any app, because window resizing belongs to macOS, not to the app.

None of these tricks needs a setting turned on, and none of them changes anything permanently — the worst case is a window shaped wrong for a second, and a drag fixes that.

When resizing isn't enough

If you're constantly hand-shaping the same two-window layouts, stop resizing and start tiling — see how to tile four windows in quarters.