Breadcrumbs

A breadcrumb trail answers two questions at once: where am I, and what is above me. It is secondary navigation, never the primary kind, and it only earns its space when the hierarchy runs deeper than two levels. The first crumb is the root, the last is the page being read, and everything between is a way back up.

By convention the current page sits last and is not a link, carrying aria-current="page" so assistive technology names it as the place you are. The trail belongs in a labelled nav landmark, and the levels belong in an ordered list, because the order is the meaning. Separators (a slash, a chevron) are decoration and are hidden from screen readers. When the trail outgrows its room, the middle collapses into an overflow menu; the first and last crumbs stay.

Breadcrumbs are regularly confused with a step indicator, which looks similar and says something else: steps describe progress through a task, crumbs describe position in a structure. They are not a back button either. Back retraces the route you actually took, while a breadcrumb draws the shape of the site, which may be a path you never walked (arriving from search drops you three levels deep with no history behind you).

The name comes from Hansel and Gretel, whose crumbs were meant to lead them home and were eaten by birds. The metaphor is imperfect in the same way the pattern often is: the trail in the tale records where you have been, while the one in an interface records where the page sits. macOS is more literal about it, calling the file system version a path bar (a path control, to developers).