How to snap windows on a Mac by dragging them to an edge

On macOS 15 Sequoia and later, you can snap a window by dragging it: take it by the title bar to the left or right edge of the screen and it fills that half, to a corner and it fills that quarter. The switch is “Drag windows to screen edges to tile”, in System Settings under Desktop & Dock. For thirds, sixths, zones you draw yourself, or snapping on macOS 14 Sonoma, you need an app such as Trill.

Here is how the built-in tiling works, what it does not cover, and what an app adds on top.

Snap windows with macOS tiling

If your Mac runs macOS 15 or later, try it first, because it may already be on.

1. Take a window by its title bar, the strip across the top.
2. Drag it until the pointer reaches the left or right edge of the screen. An outline appears showing the half it will fill.
3. Let go. The window fills that half.
4. To fill a quarter, drag to one of the screen’s corners instead. To fill the whole screen, drag the window up onto the menu bar.

If nothing happens, the setting is off. Open System Settings, choose Desktop & Dock in the sidebar, scroll down to Windows, and switch on “Drag windows to screen edges to tile”. Filling the screen from the menu bar has its own switch just below it, “Drag windows to menu bar to fill screen”.

Two other routes tile a window without dragging. Hover the pointer over the green button at the top left of a window, and its menu offers layouts under Move & Resize and Fill & Arrange. The Window menu in most apps has Move & Resize too, with halves and quarters.

Where macOS tiling stops

The built-in tiling is good at the common case, two windows side by side, and for many people that is all they need. It leaves a few gaps that send people looking for more.

No drag to tile on macOS 14 Sonoma. Drag-to-edge tiling arrived with macOS 15. On Sonoma, dragging a window to the edge of the screen just moves it there. Sonoma’s green button can still put two apps side by side in Split View, but that gives them a desktop of their own rather than placing a window among the others.

Halves and quarters only. On a wide display, two halves are often too wide to read comfortably, and thirds are what you actually want: a browser in two thirds and notes in one third, or three documents side by side. Dragging to an edge in macOS does not give you thirds, sixths or any layout of your own.

The same layout on every display. A laptop screen and a large external monitor get the same set of tiles, though they suit very different arrangements.

Moving still means the title bar. You have to find the strip at the top of a window to drag it, which is fiddly when windows overlap or a title bar is crowded with tabs and toolbars.

Snap to thirds, sixths and zones you draw

Trill is a menu bar app for trackpad gestures, keyboard shortcuts and window snapping, and it works on macOS 14 Sonoma as well as later versions. Its drag to snap starts where macOS does and goes further.

1. Drag a window to an edge of the screen for a half, or to a corner for a quarter.
2. As you drag, a translucent preview in your Mac’s accent colour shows where the window will land.
3. Hold Shift while dragging to see every zone. On an ordinary landscape display these start as thirds and sixths; portrait and ultrawide displays start with layouts suited to their shape.
4. Move the pointer into the zone you want and let go.

The zones are yours to change. You can draw your own, for each display, so a laptop screen can keep simple halves while a wide monitor gets a large centre zone with narrow columns either side, or whatever layout suits the work you do on it.

Trill needs Accessibility permission to move windows; macOS asks once. Snapping does not need a trackpad, so it works with a mouse too.

Feel the window land

On a Force Touch trackpad, Trill taps back as you drag. You feel a bump each time the preview moves to a new zone, and a tick when the window lands. It sounds like a detail, but on a big screen with several zones it means you feel each change of zone as it happens, rather than watching the preview for it. Without a Force Touch trackpad, or with a mouse, there is nothing to feel, and the preview does the job on its own. Feel a tick when a gesture works covers the other haptics and the Strength setting.

Move and resize without the title bar

This is the answer to the title bar problem, and it is off until you turn it on.

• Move: hold Control and Option and drag anywhere inside a window. The whole window follows, wherever you grabbed it.
• Resize: with the same keys held, right-drag inside the window to change its size.

Once it is on, you no longer need to aim at the top strip of a window at all.

Snap without dragging

Dragging is the most natural way to place a window, but not the fastest. Trill’s Windows Gesture Set adds two more.

Gestures. A four-finger swipe left or right sends the window in front to the left or right half. A five-finger swipe up fills the screen, and a five-finger swipe down puts the window back to its old size. If macOS already uses four-finger swipes for Spaces, Trill holds those two back until you pick a fix, as the last section explains.

Hyper Key shortcuts. The same set adds 21 shortcuts on ✦, the Hyper Key: ✦ with an arrow for halves, ✦Return to fill, ✦C to centre, ✦Delete back to the old size, ✦D, ✦F and ✦G for thirds, ✦E and ✦T for two thirds, ✦U, ✦I, ✦J and ✦K for quarters, ✦- and ✦= for smaller and larger, ✦Z to undo, and ✦N and ✦B for the next and previous display. They work once you switch the Hyper Key on in Trill’s Shortcuts screen, where Caps Lock is the key it starts with. How to turn Caps Lock into a Hyper Key on a Mac explains how ✦ works.

BetterTouchTool also does window snapping, with a live preview, custom snap areas for each display, moving and resizing while holding a modifier key, and a window switcher, as one part of a much larger app that covers far more devices and features. If snapping, a few shortcuts and some gestures are what you want, Trill keeps to those.

When macOS tiling and Trill both want the drag

If macOS’s own “Drag windows to screen edges to tile” (or “Drag windows to menu bar to fill screen”) is on, a window dragged to an edge would be tiled twice: once by macOS and once by Trill. So while it is on, Trill’s drag to snap shows “Blocked by macOS tiling”, with a one-click “Turn off macOS edge tiling” button. That stops macOS tiling windows you drag to an edge or the menu bar; the green button’s tiling still works. If you change your mind, “Turn macOS tiling back on” undoes it.

The same applies to gestures. If macOS uses four-finger swipes left and right to switch Spaces, as it may out of the box, Trill keeps its four-finger window swipes off, marks them “Blocked by macOS” and says why, and offers the fix in one click: turn the gesture off in macOS, or pick another gesture. Trill changes a macOS setting only when you click a fix like this. Every change is written down, and Put back returns them exactly as they were.

Questions

How do I snap a window to half the screen on a Mac?

On macOS 15 or later, drag the window by its title bar to the left or right edge of the screen and let go when the outline appears. If nothing happens, switch on “Drag windows to screen edges to tile” in System Settings, Desktop & Dock.

Can a Mac snap windows into thirds?

Not by dragging to an edge with macOS alone; that gives halves, quarters and full screen. Trill adds thirds and sixths when you hold Shift while dragging, plus zones you draw yourself and ✦ shortcuts for thirds and two thirds.

Can I snap windows on macOS 14 Sonoma?

Not by dragging, since drag-to-edge tiling arrived with macOS 15; Sonoma’s green button offers Split View instead. Trill runs on Sonoma and later, so drag to snap works there too.

What happens when the Trill trial ends?

Drag to snap stops, along with gestures, shortcuts and the Hyper Key, until you enter a licence key. Everything you set up, including zones you drew, is kept. Trill is $29 once, works on up to 3 Macs per key, and you can ask for a refund within 30 days.