How to Split Screen on Mac with Keyboard Shortcuts 

By Ryan Hanson, creator of Rectangle · Tested on macOS 15.5 with Rectangle 0.96 · Updated July 2026

Short version: Install Rectangle, grant it Accessibility permission, then press Ctrl+Option+Left Arrow to snap the active window to the left half of your screen and Ctrl+Option+Right Arrow for the right half. That's split screen in two keystrokes, and unlike macOS Split View it doesn't hide your other windows or break Cmd+Tab. Full setup and shortcut list below.

The fastest path to split screen

If you want the answer without the context: download Rectangle from rectangleapp.com, allow it in System Settings under Privacy & Security → Accessibility, then use these two shortcuts.

Left half — Ctrl + Option + Left Arrow

Right half — Ctrl + Option + Right Arrow

Click the window you want to move first, hit the shortcut, then click the other window and hit the opposite one. Two windows, side by side, in about four seconds. Everything below explains the setup properly and covers the rest of the shortcuts worth knowing.

Why not just use macOS Split View?

macOS has had Split View for years — hold the green button and pick a side. It works, but it comes with a real cost that catches people out: Split View pushes both windows into a full-screen space of their own. Your desktop disappears, other windows become harder to reach, and Cmd+Tab behaves differently because you've left the normal desktop entirely.

Sequoia's newer window tiling improved things and handles basic halves without going full-screen, which is genuinely better for casual use. But it still lacks size cycling, sixths, and custom shortcuts. A dedicated app keeps windows on your regular desktop, snaps them instantly by keyboard, and lets you keep working the way you already do. That's the difference people notice within a day.

Step-by-step setup

Step 1 — Install Rectangle

Download the Rectangle app from the official site, or if you use Homebrew:

brew install --cask rectangle

It's free and open source, so there's nothing to buy and no account to create.

Step 2 — Grant Accessibility permission

On first launch, Rectangle asks for Accessibility access. macOS opens System Settings → Privacy & Security → Accessibility, where you switch Rectangle on. This is required — macOS won't let any app move windows without it, and every window manager needs the same permission. If snapping doesn't work later, this toggle is the first thing to check.

Step 3 — Snap your first two windows

Click the window you want on the left, press Ctrl + Option + Left Arrow. Click the second window, press Ctrl + Option + Right Arrow. Done — that's a split screen, and both windows stay on your normal desktop where Cmd+Tab still works exactly as expected.

The shortcuts worth memorizing

You only need the first two to split a screen, but these are the ones that become muscle memory fast.

Left half — Ctrl + Option + Left Arrow

Right half — Ctrl + Option + Right Arrow

Maximize — Ctrl + Option + Enter

Center — Ctrl + Option + C

Top half — Ctrl + Option + Up Arrow

Bottom half — Ctrl + Option + Down Arrow

Next display — Ctrl + Option + Cmd + Right Arrow

Previous display — Ctrl + Option + Cmd + Left Arrow

Every one of these is remappable in Rectangle's settings if the defaults clash with another app or don't suit your hands.

The trick most people miss: size cycling

Here's the feature that changes how you use split screen. Press the same shortcut twice in a row and the window cycles to a different width — hit Ctrl+Option+Left once for a half, again for a third, again for two-thirds. One key combination covers several layouts, so you stop thinking about which shortcut produces which width and just tap until it looks right.

This is why a two-thirds and one-third split is as easy as a fifty-fifty one. On a wide monitor it's the difference between a usable layout and a cramped one, and it's the single thing macOS native tiling has no answer for.

Splitting three or more windows

Two windows is the common case, but thirds and sixths open up more. Use the thirds shortcuts (or cycle into them) to put three windows side by side — a browser, an editor, and a terminal, for instance. On an ultrawide, sixths let you run six columns without anything overlapping.

The practical limit isn't the app, it's your screen width. On a 13-inch laptop, two windows is usually the sensible maximum. On a 34-inch ultrawide, three or four is comfortable, and that's where a keyboard-driven approach really pays off, because dragging that many windows by hand gets tedious fast.

Drag-to-snap, if you prefer the mouse

Rectangle also does the Windows-style thing: drag a window to a screen edge and it snaps to that half, corner for a quarter, top for maximize, with a translucent preview showing where it'll land before you let go. If you switched from Windows and miss Win+Arrow and drag-to-edge, this covers both halves of that habit — keyboard shortcuts and mouse snapping in the same app.

When something doesn't work

Nine times out of ten, shortcuts failing means the Accessibility permission got reset, which commonly happens after a macOS update. Go back to System Settings → Privacy & Security → Accessibility, remove Rectangle, add it again, and restart the app. The other common cause is a shortcut conflict with another app claiming the same key combination — remap either side and it's solved.

Frequently asked questions

What's the keyboard shortcut to split screen on Mac?

With Rectangle installed, Ctrl + Option + Left Arrow snaps the active window to the left half and Ctrl + Option + Right Arrow to the right half. Do one, then the other with a second window, and you have a split screen. macOS alone has no equivalent single-keystroke shortcut for this.

Can you split screen on a Mac without an app?

Yes, partially. macOS Split View (hold the green button) and Sequoia's built-in tiling both split windows without extra software. Split View pushes windows into a full-screen space, and native tiling lacks size cycling, sixths, and custom shortcuts — which is why many people install a dedicated app instead.

How do I split screen into three windows on a Mac?

Use thirds. In Rectangle, the thirds shortcuts (or repeat-pressing a halves shortcut to cycle into a third) place windows in left, center, and right columns. Three windows works comfortably on displays 27 inches and wider; on a laptop screen, two is usually the practical limit.

Why does my Mac split screen shortcut stop working?

Almost always the Accessibility permission was reset, typically by a macOS update. Re-grant it in System Settings → Privacy & Security → Accessibility and restart the app. The other frequent cause is another app claiming the same keyboard shortcut, which you fix by remapping one of them.

Written and tested by Ryan Hanson, creator of Rectangle, on macOS 15.5.