Sash vs. Rectangle
Rectangle is the app most people recommend for Mac window management, and it deserves it. This page is about the one question that matters: what do you need that Rectangle doesn't do?
Short answer: if halves, quarters, and thirds are all you want, use Rectangle. It's free, open source, and good. If you came from Windows and miss what happens after the snap — Snap Assist, Snap Groups, an Alt-Tab that shows windows — that's Sash. Basic snapping in Sash is free too, so you give up nothing by switching.
At a glance
| Feature | Rectangle | Sash |
|---|---|---|
| Price | Free (Pro $9.99 once) | Free snapping / $19.99 once for Pro |
| Keyboard snapping (halves, quarters) | Yes | Yes (free) |
| Thirds & two-thirds | Yes | Yes (Pro) |
| Drag to edge to snap | Yes | Yes |
| Snap Assist (fill the empty zone) | No | Yes (Pro) |
| Snap Groups (switch to a pair as one) | No | Yes (Pro) |
| Resize a pair with one divider | No | Yes (Pro) |
| Alt-Tab with window thumbnails | No | Yes (Pro) |
| Custom snap targets, app pinning | Pro | No |
| Open source | Yes | No |
| Mac App Store | Pro only | No (signed & notarized download) |
| Trial | n/a (free) | 14 days, no card |
Snapping: a tie
Both apps snap to halves, quarters, and thirds with hotkeys or by dragging to a screen edge. If you have Rectangle's shortcuts in your fingers, Sash lets you rebind to match. Rectangle Pro goes further on snapping itself, with custom snap targets anywhere on screen and per-app pinning. If your wish list is more kinds of snapping, Rectangle Pro is the better buy.
After the snap: where they split
Snap a browser to the left half. Now what? On Windows 11 the empty right half fills with a picker of your other windows and you choose one. Rectangle leaves the space empty and you go find the next window yourself. Sash shows the picker. That's Snap Assist, and it's the feature people search for without knowing its name.
Once two windows are side by side, Sash treats them as a Snap Group: switch to both at once, resize both with one divider, and see them as a pair in the switcher. Rectangle has no concept of a group. Two snapped windows are two unrelated windows.
Alt-Tab
Neither Rectangle nor macOS changes ⌘-Tab, which cycles apps and shows one icon per app no matter how many windows are open. Sash adds a real Alt-Tab: hold ⌥, tap ⇥, cycle window thumbnails. If you only want a switcher, the free open-source app AltTab does this well. Sash's case is that the switcher knows about groups and snapping, so it's one app instead of two that don't talk to each other.
Price
Rectangle is free. So is snapping in Sash. The $19.99 one-time Pro license buys the three things Rectangle doesn't ship, on two Macs, with free updates and no subscription. If you don't want those three things, don't pay for them.
Who each is for
- Rectangle: you want free, well-maintained snapping and nothing more. Or you want to customise the snapping itself, in which case Rectangle Pro.
- Sash: you came from Windows, you multitask in pairs of windows, and you switch between windows constantly. Try it free for 14 days, no card required.
Common questions
Is Rectangle free?
Yes. Rectangle is free and open source. Rectangle Pro is a $9.99 one-time upgrade that adds custom snap targets, app pinning, and saved arrangements. Basic snapping in Sash is also free forever.
Can I run Sash and Rectangle at the same time?
Yes, as long as they use different hotkeys. Most people try Sash alongside Rectangle for a few days during the trial, then keep one.
Does Rectangle have Snap Assist or an Alt-Tab switcher?
No. Rectangle stops at the snap. It has no Snap Assist to fill the empty half, no Snap Groups, and no window switcher. Those three are what a Sash Pro license adds.
See also: Sash vs. Magnet · all Mac window managers compared · pricing