In this guide
The short version
| Rectangle | Magnet | Moom | |
|---|---|---|---|
| Licence | Open source, free | Paid, App Store | Paid, one-off |
| Primary input | Keyboard | Drag to edges | Grid popover |
| Halves and quarters | Yes | Yes | Yes |
| Thirds and sixths | Yes | Yes | Yes |
| Size cycling | Yes | Limited | Via grid |
| Saved layouts | Paid tier | No | Yes |
| Custom grid | Paid tier | No | Yes |
If you want a keyboard-driven tool that costs nothing and does the job, Rectangle is the straightforward answer and the reason it has become the default recommendation. If you strongly prefer dragging windows to screen edges, Magnet is built around that gesture. If you need arbitrary saved grids and a mouse-driven interface, Moom is the specialist.
Rectangle: keyboard-first and open source
The design assumption is that you would rather press a key than move a pointer. Every position — halves, thirds, quarters, sixths, two-thirds — has a default shortcut, and cycling lets a single combination reach several sizes. Drag-to-edge snapping exists too, so it is not exclusively a keyboard tool, but the keyboard is clearly where the thinking went.
Being open source has practical consequences beyond price. The source is inspectable, which matters for a utility that requires Accessibility permission; it is not tied to an App Store account; and it has survived several macOS releases without the abandonment risk that affects small commercial utilities. The paid tier adds saved layouts and window history, but the free build covers every layout described anywhere on this site.
Requiring Accessibility permission is not a red flag by itself — every window manager needs it, because macOS cannot move another application's windows without it. It is, however, a good reason to prefer software whose source you can inspect.
Magnet: built around the drag
Magnet's central gesture is dragging a window to an edge or corner and having it snap. It does this well, with a clear preview overlay, and for people who work primarily with a trackpad it feels more natural than memorising key combinations. It also has keyboard shortcuts, but they are the secondary interface rather than the point.
It is paid, sold through the App Store, which some people prefer for the update mechanism and sandboxing assurances. Where it loses to alternatives is depth — no saved layouts, no custom grids, and less flexibility in how sizes cycle. For a user who wants halves and quarters and nothing more, that simplicity is arguably a feature.
Moom: grids and saved arrangements
Moom takes a different approach entirely. Hovering the green button of a window produces a small grid popover; you drag across it to define an arbitrary rectangle. It also saves complete multi-window arrangements and can reapply them, including automatically when a particular display is connected.
This is genuinely powerful for people whose work has a small number of fixed, complex setups — a five-window trading screen, a specific editorial arrangement. The cost is that the primary interface is mouse-driven and there is more configuration to do before it pays off. Keyboard users often find they are fighting the design rather than using it.
What about the built-in macOS tiling?
Recent macOS versions include window tiling of their own — drag to an edge, or use the Window menu, and get halves and quarters with keyboard shortcuts. For a user who only ever wants two windows side by side, this may well be enough, and it is worth trying before installing anything.
The gaps show up quickly with heavier use: no thirds or sixths, no cycling, less control over gaps and margins, and no saved layouts. Most people who move to a dedicated tool do so because they wanted three columns rather than two. There is more on this comparison in our dedicated guide, and either way the Rectangle app coexists with the built-in feature without conflict.
Picking one
- You type more than you point — Rectangle.
- You live on the trackpad and want edge snapping — Magnet.
- You need complex saved arrangements and like grids — Moom.
- You want to spend nothing and inspect the source — Rectangle.
- You only ever need two windows side by side — try the built-in tiling first.
A reasonable strategy for the undecided: start with the free open-source option, since it costs nothing to try and covers the majority of use cases. If after a fortnight you find yourself wanting saved multi-window arrangements, you will then know precisely what you are paying for rather than guessing.
Rectangle is free and open source
Halves, thirds, quarters and sixths from the keyboard, on any Mac. No trial, no account.
Download Rectangle for Mac →Frequently asked questions
Can I run two window managers at once?
Technically yes, practically no. They will compete for the same shortcuts and produce intermittent failures.
Is the paid Rectangle tier worth it?
Only if you rebuild the same complex multi-window arrangement regularly. For everyday halves and thirds, the free build is complete.
Do any of these slow down a Mac?
No. They are lightweight utilities that act only when a command is issued.