The window manager for ultrawide Macs
A 34-inch or 49-inch ultrawide is wonderful until every window ends up in the middle. Kumiko gives the screen a shape you can use.
Updated
Why ultrawides need a different window manager
Most window managers were designed for laptop screens, where splitting the screen in half is the obvious move. On a 21:9 monitor, half the screen is about 1,700 pixels wide; on a 32:9 monitor it's 2,560. That's wider than most apps were designed for, and your eyes end up travelling across a page of mostly empty space.
What works better on an ultrawide is what people do with three physical monitors: one main window straight ahead, with reference windows either side. Kumiko does that without you placing anything by hand.
Arrow keys that know how wide your screen is
Hold ⌃⌥ and press an arrow. On a normal screen, ← sends the window to the left half, and pressing again cycles through ⅔ and ⅓. On an ultrawide, the order changes so the first press gives you a third. ⌃⌥ ↑ puts the window in the centre column (straight in front of you), and ⌃⌥ ↓ puts it back where it was. Two arrows in a row make a corner.
Six layouts shaped for 16:9, 21:9 and 32:9
Instead of placing windows one at a time, pick a layout and every window on that display moves at once:
| Shortcut | Layout | What it does |
|---|---|---|
| ⌃⌥ 1 | Focus centre | Your main window straight ahead, reference windows either side. Made for ultrawides. |
| ⌃⌥ 2 | Halves | Main window on the left half, everything else stacked on the right. |
| ⌃⌥ 3 | Thirds | Main window in the centre third, the rest left and right. |
| ⌃⌥ 4 | Studio | A big canvas with your tools in a column beside it. Good for design and video. |
| ⌃⌥ 5 | Stack | Main window on the left, a tidy grid of the rest on the right. |
| ⌃⌥ 6 | Columns | Equal columns for comparing things side by side. Up to six on an ultrawide. |
Each layout changes shape with the screen. On a 16:9 display, Focus centre gives the main window most of the width; on a 32:9 display it becomes a true centre column with room on both sides.
Ask instead of arranging
The bigger the screen, the more windows you have open, and the more tedious arranging them gets. Press ⌥ Space and type what you're doing: "review PR 482 and reply to the team" or "get ready for the checkout design review". Kumiko finds the right windows, opens what's missing, brings the right browser tab forward and shows you the plan before it moves anything.
Everything else an ultrawide setup needs
- Meeting mode moves the call to the top middle, right under your webcam, so you look at people instead of off to one side.
- Share-safe blurs chat, mail and other private apps when you share that huge screen.
- Resume brings back every tab and folder after a restart or when you plug the monitor back in.
- Per-display layouts: the ultrawide and your MacBook each remember their own.
Shortcuts at a glance
| ⌥ Space | Ask Kumiko (the command bar) |
| ⌃⌥ ← → | Left or right side; press again for ½, ⅔, ⅓ |
| ⌃⌥ ↑ ↓ | Top or bottom; on an ultrawide, ↑ is the centre column |
| ⌃⌥ ← then ↑ | Two arrows make a corner |
| ⌃⌥ ↩ | Fill the screen |
| ⌃⌥⌘ ← → | Move the window to the next display |
| ⌃⌥ 1–6 | The six layouts |
| ⌃⌥ 0 | This display's usual layout |
| ⌃⌥ P | Blur the app you are in (Share-safe) |
| ⌃⌥ Q…C | Optional letter grid (turn it on in Settings › Shortcuts) |
Every shortcut can be changed in Settings. Kumiko works on macOS 14 or later.
Kumiko is €30 once for 2 Macs, and the first 25 launch licences are €9. It works on macOS 14 or later.
Questions
What is the best window manager for an ultrawide monitor on Mac?
One that changes its snap positions for the shape of the screen. On a 34" or 49" ultrawide, half the screen is too wide for most apps, so you want thirds, a centre column and layouts for three to six windows. Kumiko is built around that; Rectangle, Magnet and Moom can do thirds but use the same positions on every screen.
Does macOS support ultrawide window snapping?
macOS 15 and later can tile windows to halves and quarters. It has no thirds or centre column, which are what make an ultrawide comfortable.
Does Kumiko work with a 32:9 super ultrawide like the Samsung Odyssey G9?
Yes. Kumiko reads each display's shape, so 32:9 gets narrower thirds and up to six columns, while 21:9 gets layouts that suit it.
What if I use an ultrawide and a MacBook screen together?
Each display keeps its own layout. The ultrawide can run Focus centre while the MacBook runs Halves, and ⌃⌥⌘ with an arrow moves a window from one to the other.
Setting up a new monitor? See how to set up an ultrawide monitor on a Mac.