Command Palette

Also called ⌘K menu, spotlight, quick switcher, command bar, command menu

A searchable overlay, usually opened with a keyboard shortcut, listing actions and destinations that filter as the user types.

Example

In a real product this opens with ⌘K — and the shortcut is shown somewhere permanent, because a palette nobody can find does not exist.

The product has more actions than any menu can hold comfortably — dozens of commands, hundreds of documents.
People use it daily. The shortcut only pays off once it is in muscle memory.
Navigation and actions live in different places, and jumping between them by pointer is slow.
You want one predictable entry point for search, navigation and commands at once.

It is the only way to reach something. Every command in the palette needs a visible home too, or the feature does not exist for most users.
The app has a handful of actions. A palette over five commands is ceremony.
The audience is occasional or first-time users, who will never discover a shortcut nobody told them about.
You are tempted to put a destructive action in it. Fuzzy matching plus a fast Enter is a bad combination for anything irreversible.

Fastest possible path for someone who knows what they want.
Costs no permanent screen space.
Doubles as a discovery tool — typing a vague word reveals commands the user did not know existed.

Undiscoverable by nature; it needs a visible hint somewhere to exist at all.
Useless to pointer-only and touch users unless you also expose a button.
Needs constant upkeep — a palette missing half the app's commands is worse than none, because it teaches people not to trust it.

What this pattern needs in order to work for everyone.

Keyboard: The shortcut must not collide with browser or assistive-tech bindings. ⌘K and Ctrl+K are conventional for a reason.
Arrow keys move through results, Enter runs the highlighted one, Escape closes and returns focus to where it was.
Focus goes to the input on open — the user is expected to type immediately.
Roles and state: It is a combobox pattern: the input owns `role="combobox"`, the results are a `listbox`, and each result is an `option`.
Use `aria-activedescendant` so the highlighted item is announced while focus stays in the input.
Announce the result count as it changes, or a screen reader user cannot tell whether typing narrowed anything.
Focus: Focus stays in the input the entire time — arrow keys move a visual highlight, not focus itself. That is what allows typing and navigating at once, and it is the part most hand-rolled implementations get wrong.

Linear — Arguably the product that made the pattern an expectation; nearly every action is reachable from it.
VS Code — The command palette predates the current trend and still sets the bar for breadth.

Side-by-side breakdowns of patterns that solve a similar problem.