How to save a window layout on a Mac and bring it back with a shortcut

macOS can't save where your windows sit. Sashay can: save the windows on your screens under a name, such as Desk or Writing, then press that layout's shortcut to put every window back.

What macOS offers

macOS 15 and later can tile a window into halves and quarters from the Window menu, or when you drag it to the edge of the screen. It can't save a set of windows and bring them back later.

Fix it with Sashay

Download Sashay, drag it to Applications and open it. Click Open Accessibility Settings and switch Sashay on.
Arrange your windows the way you like them.
Right-click Sashay's menu bar icon, choose Named layouts, then Save these windows as a named layout….
Type a name, such as Desk, and click Save. The first layout gets Control-Option-Command-1, the next one 2, and so on up to 9.
Move some windows, then press Control-Option-Command-1. They go back where you saved them, and a note offers Undo.

A layout remembers each set of screens you save it on. Save Desk once at your desk with the monitor and once on the MacBook alone, and the same shortcut fits whichever screens are connected.

More you can do

Open closed apps too. In Settings, under Named layouts, switch on Open a layout's closed apps when you choose it. Sashay opens any app in the layout that isn't running, then puts its windows in place.
Pick your own shortcut. Under Named layouts in Settings, click a layout's shortcut and press the keys you want. You can rename and delete layouts there too.
Tile in one move. Right-click the menu bar icon and choose Tile windows on this screen to place the front windows in one of eight shapes, from two side by side to a grid of four.

Sashay keeps its layouts on your Mac and stores window titles only as one-way hashes, never as text.

If it doesn't work

A window didn't go back. Sashay moves windows on each screen's current desktop. Windows on other desktops stay where they are in this version.
The shortcut does nothing. Another app may use the same keys. Give the layout a different shortcut in Settings.