Tooltip
Tooltips display additional information upon hover or focus that is contextual, helpful, and provides clarity to a user.
Overview
Keyboard interactions
The primary use of tooltips is to display the text labels of icon-only buttons. Since each button is in the page’s tab order, the tooltip appears automatically when the button receives focus. Tooltips disappear when the user moves focus away from the button or by pressing Esc. The tooltips contain only text and are not interactive, so they do not have any other keyboard operations.
The definition tooltip provides information about a term or text phrase. The text that serves as the trigger has a dotted underline. When the trigger receives focus, the definition tooltip is displayed. Like the button tooltip, the definition can be dismissed by pressing Esc or navigating away from the trigger. Icon-only buttons retain their regular interaction. Icon-only buttons maintain their normal interaction and can be activated by clicking or pressing Enter or Space. A definition tooltip trigger only exists to take focus or hover and is otherwise not interactive.
Design recommendations
Annotate the text for the tooltip
If designers do not specify the text, developers are less likely to implement tooltips. Every icon-only button needs a tooltip, except for icons with clearly established names or functions (such as Bold and Italics). Designers can provide the text by using a tooltip in their designs or simply annotating the icon-only button.
Development considerations
Use as title attribute. Tooltips are progressive enhancements for the title attribute, and will display as the title attribute if the component doesn’t initialize.
Tooltips make title attributes keyboard accessible.