Snackbar
A short-lived message near the bottom of the screen, often with one action such as Undo.
See it
What it is
A snackbar is a brief message near the bottom of the screen that can offer one contextual action. Gmail's 'Conversation archived' strip with its Undo button is the version almost everyone has used. Google introduced the name through Material Design. It overlaps heavily with toast in everyday product language, but snackbar usually implies the low strip and its optional action button.
Reach for one after a lightweight action when confirmation helps and a quick reversal is useful. Undo is the ideal action because it keeps the main task moving. Queue snackbars instead of piling them over one another, and keep permanent history or important status somewhere the user can revisit.
Gotcha: auto-dismiss makes it the wrong home for errors, decisions, or instructions someone must read. Pause the timer while the snackbar or its action has keyboard focus, announce the message through a polite live region, and leave room for mobile safe areas and bottom navigation. If Undo disappears before someone can reach it, the action was never really available.
Ask AI for it
Build a Material Design style snackbar for 'Conversation archived' with one Undo button. Place it fixed near the bottom center above env(safe-area-inset-bottom), max-width 36rem, with a dark surface, high-contrast text, rounded corners, and a clearly labelled action. Expose the message through an aria-live='polite' region, auto-dismiss after 6 seconds, pause that timer on hover and focus, and close after Undo succeeds. Queue later messages so only one snackbar is visible. Animate with transform: translateY() plus opacity, disable motion under prefers-reduced-motion, and never cover a mobile tab bar.