i3 on a Mac: pick the part you miss

Why i3 and sway don't run on macOS

i3 is a tiling window manager for X11, and sway is its Wayland twin, which even reads an i3 config. Both need to be the window manager for the whole display session. On a Mac that job belongs to Apple. A Mac tiler is a normal app that moves other apps' windows through the Accessibility API, so the best anyone can do is copy i3's behaviour.

First, which part of i3 do you miss?

Be specific, because no single Mac tool copies all of i3:

• The tree. Containers inside containers, with splith and splitv, and you decide where the next window goes.
• Tabbed and stacked containers. $mod+w and $mod+s to fold a container down to one visible window.
• Numbered workspaces. $mod+1 to $mod+9, instant, no animation.
• The config file. One plain-text file you keep in dotfiles and reload.
• Keyboard only. You almost never touch the mouse.
• Nothing overlaps. Every window has a place and stays there.

Keep that list in mind as you read the options.

AeroSpace: the closest to i3

AeroSpace calls itself an i3-like tiling window manager, and it means it. Windows live in an i3-style tree with four layouts: h_tiles and v_tiles for splits, and h_accordion and v_accordion, which play the roles of i3's tabbed and stacked. Floating windows sit outside the tree.

It has its own workspaces, which behave more like i3's than macOS Spaces do. To do that it ignores macOS Spaces and parks hidden windows just off a bottom corner of the screen. You configure it with a TOML file and drive it from a CLI. It's free (MIT), runs on macOS 13 and later, and never needs SIP changes.

The trade-offs: it's still a public beta with breaking changes expected before 1.0, there's no GUI for settings and the project says there never will be, and it recommends turning "Displays have separate Spaces" off. Ribbon vs AeroSpace and AeroSpace alternatives go deeper.

yabai with skhd: tiling that works with Spaces

yabai tiles with binary space partitioning, with bsp, stack and float layouts per Space. It has no hotkeys of its own, so you pair it with skhd, a separate hotkey daemon, to play the part of i3's bindsym lines. Its config is a shell script, yabairc.

Unlike AeroSpace, yabai uses native macOS Spaces. That keeps Mission Control and full-screen apps working, but some of the most i3-like features, such as creating, destroying and moving Spaces, scratchpad windows and sticky windows, need System Integrity Protection partly disabled. Read yabai without SIP to see what still works with SIP on.

Pick yabai if you like scripting your desktop and you're comfortable with the SIP trade-off for the extras.

Amethyst: automatic layouts, less fiddling

Amethyst is modelled on xmonad rather than i3. You don't build a tree. You pick a layout, such as Tall, Wide, Column or BSP, and Amethyst places every window for you. It has a preferences window plus an optional YAML file, uses native Spaces, and needs only Accessibility. It's free (MIT).

Pick it if what you liked about i3 was "windows arrange themselves" and you never enjoyed managing splits by hand.

Ribbon: for when you're tired of the shrinking

In i3, each new window splits a container, so your windows get smaller as you open more. Tabbed containers help, but then you can only see one window at a time.

Ribbon takes a different route. Every window sits in a column on a horizontal strip that's wider than the screen. A new window adds a column, the others keep their width, and the strip scrolls to the focused one. You still get keyboard-first control (⌃⌥H / ⌃⌥L to move focus, ⌃⌥⇧H / ⌃⌥⇧L to move a window), nothing overlaps, and a column can hold a stack of windows or show them as tabs with ⌃⌥⇧T.

What it doesn't have, compared with i3: no tree and no splits in two directions, no workspaces of its own (it uses macOS Spaces, one strip each), and no text config. Every option is in a settings window. It's paid ($9.99 once), runs on macOS 13 and later on Apple silicon (M1 or later), and needs only Accessibility. If the idea is new, what a scrolling window manager is explains it, and the live demo shows it in your browser.

i3 concepts on each Mac tool

Getting i3's numbered workspaces on a Mac

With AeroSpace you get them out of the box. With the other three you use macOS Spaces. Add Spaces in Mission Control, then turn on "Switch to Desktop 1" and the rest under System Settings → Keyboard → Keyboard Shortcuts → Mission Control, and ⌃1, ⌃2 and so on switch Spaces. It's not as instant as i3, because macOS plays its slide animation.

Note that in Ribbon ⌃⌥1–⌃⌥9 jump to a window on the strip, not to a workspace.

Which should you choose?

• You want i3, as close as possible: AeroSpace.
• You want i3's power and don't mind scripting or SIP changes: yabai with skhd.
• You want tiling without managing splits: Amethyst.
• You want keyboard-first, non-overlapping windows that never shrink: Ribbon. See pricing.

If you only want to snap a window to half the screen now and then, you don't need any of these; how to tile windows on a Mac covers macOS's built-in tiling.