Noun The ability to show/hide items based on certain properties of the items.

Distinct from sorting, where all items are shown but ordered according to certain criteria. Filtering items does not in itself indicate an order, though a sort order can also be applied to the items, including sorting that groups items by the properties used for filtering. Filters can correspond to multiple properties of each item.

Generally, more than one filter can be applied at the same time. UIs where the user selects between mutually exclusive options are better implemented via other patterns like tabs, segmented controls, or any sort of category navigation.

Often a ‘All’ option is useful to quickly select or deselect all filters. One implementation is where the relationship between the ‘All’ option and the entire set of filters is one of mutual exclusivity. The ‘All’ option, separate from the filters, deselects all filters when selected. The user can opt to select individual filters, toggling deselection the ‘All’ option it the process. Another implementation is where a ‘Select All’ option merely selects all filters and, ideally, a ‘Select None’ option allows quick deselection of the filters.

Always allow the user to select the filters they want to apply rather than having to deselect the filters they don’t want applied.

Contrast with: Sorting