Combobox vs Command Palette
Same machinery, opposite jobs. Both are an input joined to a filtered list, and both use the identical ARIA pattern — which is why they get confused. But a combobox answers a question the form asked and hands back a value; the palette asks its own question and then does something. That difference decides everything else: a combobox lives inside a field, is reached by Tab, and belongs to one piece of data. A palette floats over the whole app, is reached by a shortcut, and belongs to no field at all.
Filling in a value is a combobox. Carrying out an action is a command palette.
Combobox
An input paired with a list of options that narrows as the user types, used to pick one or more values.
Reach for it when
- There are more options than a plain select can present comfortably — roughly a dozen and up.
- The user usually knows what they are looking for, so typing three letters beats scrolling.
- The list is long but finite and known: countries, currencies, repositories, teammates.
- You need to pick several values and want them shown as removable chips.
Avoid it when
- There are two to five options. Radios or a plain select show everything at once and need no typing.
- Any text is valid. That is a plain input; forcing a match on free text only frustrates people.
- The user does not know the vocabulary. If they cannot guess a word to type, filtering helps nobody — show a browsable list instead.
- The choice triggers an action rather than setting a value. That is a command palette or a menu.
Command Palette
A searchable overlay, usually opened with a keyboard shortcut, listing actions and destinations that filter as the user types.
Reach for it when
- 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.
Avoid it when
- 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.