Why one shortcut does different things in different Mac apps
Most Mac shortcuts belong to the app in front, not to macOS. Each app lists its commands in its own menus and chooses the keys for them, so Command-K (⌘K) is Connect to Server in Finder, Add Link in Mail and Clear to Start in Terminal. Only a short list of shortcuts is shared by convention, and a few are taken by macOS itself before any app gets to see them.
Once you know which of those three groups a shortcut belongs to, most of the surprises make sense. Here is how it works, where the same keys part ways in apps you already use, and how to check what a shortcut does before you press it.
Three kinds of shortcut
Every key combination you press goes through roughly three owners.
macOS itself. A set of system-wide shortcuts works in every app because macOS handles them first: Command-Space for Spotlight, Command-Tab for the app switcher, Command-Shift-3, 4 and 5 for screenshots, Control-Up Arrow for Mission Control. You can see and change most of them in System Settings > Keyboard > Keyboard Shortcuts; a few, such as Command-Tab, are not listed there.
Other apps running in the background. Launchers, clipboard managers and window tools in the menu bar often register global shortcuts that work everywhere. Like the system ones, they are caught before the app in front sees them.
The app in front. Everything else is up to the app you are using. Most of its shortcuts appear in its menu bar, next to the command they run. Some are handled inside the app without any menu item at all.
So if a shortcut does something unexpected, or nothing, the question is which of the three owners got to it.
The shortcuts every app agrees on
Apple’s design guidelines ask apps to keep a core set of shortcuts for the same jobs, and almost every Mac app does:
- Command-C, Command-X and Command-V to copy, cut and paste; Command-Z to undo
- Command-A to select all, Command-F to find
- Command-N for new, Command-O to open, Command-S to save, Command-P to print
- Command-W to close a window, Command-Q to quit, Command-H to hide the app
- Command-M to minimize, Command-Comma for the app’s settings
These feel universal because they are. Beyond this list, each app’s developers choose, and they choose for their own app’s needs.
Where the same keys part ways
Here is what a few shortcuts do in four apps that ship with every Mac, read from their menus:
| Keys | Finder | Safari | Terminal | |
|---|---|---|---|---|
| ⌘K | Connect to Server | no menu item | Add Link | Clear to Start |
| ⌘D | Duplicate | Add Bookmark | no menu item | Split Pane |
| ⌘R | Show Original | Reload Page | Reply | Allow Mouse Reporting |
| ⌘E | Eject | Use Selection for Find | Use Selection for Find | Use Selection for Find |
| ⌥⌘L | Downloads | Show Downloads | Apply Rules | Clear to Previous Bookmark |
A few patterns show up. Command-E is a text command in Safari, Mail and Terminal, but Finder, which mostly works with files and disks, gives it to Eject. Option-Command-L opens Downloads in both Finder and Safari, while Mail uses the same keys to apply its rules. And Command-K means “link” in Mail and Notes, as it does in many writing apps, while Finder and Terminal use it for something else entirely.
Terminal is the clearest case of all. Command-C copies, as everywhere, but Control-C goes to the program running in the window, where it usually stops it. Command keys belong to the Terminal app, and Control keys belong to the shell inside it. Terminal shortcuts on a Mac goes further into that split.
Apps that also run on Windows add another layer. They often carry their own long-standing shortcuts over, mapping the Windows Control key to Command, which is why some of their keys feel unlike other Mac apps.
Shortcuts that live outside the menus
Not every shortcut is written down in a menu. In Finder, Space opens Quick Look, even though the File menu lists Quick Look under Command-Y. In Safari, Space scrolls the page down a screen. Design and video apps lean on single letters to pick tools, and hardly any of those appear in a menu.
That matters when you go looking: anything you find in the menus is only part of an app’s keyboard. For the rest, the app’s own help pages or a cheat sheet are the only places to look.
How to check what a shortcut does in the app in front
Open the menus. Every menu item with a shortcut shows its keys on the right. It takes a minute per app and teaches you more than any list.
Search the Help menu. Press Command-Shift-Slash (⇧⌘/), which is Command-Question Mark, and the Help menu opens with its search field ready. Type part of a command’s name. The results include matching menu items; point at one and macOS opens that menu and shows you the item, with its shortcut.
See the whole keyboard at once. Typebar does this for the app in front: hold Command, Option, Control or Shift for a moment and the keys on its on-screen keyboard relabel with what they do in that app. It reads each app’s own menus, so in Finder ⌘K is labeled with Finder’s command and in Mail with Mail’s. For 20 apps, including Finder, Safari and Terminal, it adds hand-made packs for shortcuts the menus leave out. See every keyboard shortcut for the app you are using compares this with the built-in ways.
Name it as you press it. When you teach or record, Typebar’s keystroke pill names each shortcut with the name it has in the app you are using, so viewers see the same words they will find in their own menus.
When two shortcuts collide
If an app’s shortcut does nothing, something else probably caught it first. Check System Settings > Keyboard > Keyboard Shortcuts for a system shortcut on the same keys, and think about which background apps you have running with global shortcuts. Change or untick the one you use less.
You can also change an app’s own shortcut. In the same Keyboard Shortcuts window, choose App Shortcuts, click the add button, pick the app, type the menu command’s name exactly as it appears in the menu, and press the keys you want. Choose All Applications instead of one app and every app with a menu item of that exact name gets the same keys. Add or change a keyboard shortcut for any menu item walks through it step by step.
Before you pick new keys, it helps to know which ones the app leaves free. Which keys does an app leave free? shows how to find them.
Typebar is $9 once, with a 24-hour free trial, on macOS 14 or later.
Questions
Why does Command-K do something different in every app?
Because each app chooses its own shortcuts beyond the shared basics. macOS reserves only a handful of keys, and the rest belong to the app in front.
Which wins if macOS and an app use the same shortcut?
macOS does, and so do global shortcuts set by other running apps. The app in front never receives those keys unless you change or turn off the other shortcut.
Can I make one shortcut do the same thing in every app?
Only for a command that exists in each app’s menus under the same name. Add it under App Shortcuts with All Applications chosen.