- Where to find it
- Labelled Width in the Collection Settings drawer (gear in the collection header).
- Per device
- Yes — you can set one value for every screen, or separate values for phone, tablet, and desktop.
- Underlying CSS
width
In plain English
By default the collection fills whatever space the parent gives it. Width lets you pin or size that outermost box.
For a readable centred block, Max Width plus Margin of "auto" is usually a better recipe than a fixed Width alone.
When you would use it
- The collection must be an exact width rather than filling its parent slot.
How to change it
- Open Collection Settings, then "Width", and pick a unit or auto.
One value, or one per device? Every input in this setting sits under a “Same value for all resolutions” checkbox. Leave it checked for a single value everywhere, or uncheck it to give phones, tablets, and desktops their own. How per-device values work.
Watch out for
- This setting is left out on the editing canvas so the drag-and-drop surface stays full size. Open Preview to see it applied.
Related settings
For developers
The technical reference for what this setting produces: MDN: width. You do not need any of it to use the setting — it is there for whoever is building the components or debugging the published page.
Where to go next
- Back to the full attribute reference
- The Composer — the editing surface these settings live in.
- Publishing — how a change like this reaches your live site.