A toggle is a small, movable switch that can have two positions, on or off. It is a common control element found in options menus and other types of user interfaces.
When using toggles it is important to always make the switch’s state clear through direct labeling and standard visual design. It is also important to evaluate the societal and cultural implications of using specific colors for toggle states and be mindful that not all users will associate certain colors with their expected meanings. For example, the use of red to indicate an on state may be counterintuitive for users from cultures that associate red with stop signs or traffic lights.
Generally speaking, toggles should be used sparingly. They should only be present where the user is required to update preferences, settings or other configuration items. A judicious application of toggles can greatly improve the usability of your product or site.
Many teams opt to move the toggle configuration out of the code file and into some type of centralized store, usually an existing application database. This is a much more robust solution but will require some form of Admin UI for the team to view and modify toggles.