A toggle allows people to manage the state of a view or piece of content. A toggle is typically indicated by an interface icon that communicates its purpose, and updates its appearance based on its state. Unlike other forms of selection, toggles only allow for two opposing values that are mutually exclusive. Toggle can be used to enable or disable features, or to present different views of the same data. A toggle is also a great choice for limiting the number of choices available to users, or when a list would be inappropriate.

In order to make it easy for users to understand the purpose of a toggle, designers should choose an icon and color that conveys its state. They should also evaluate the societal and cultural context for their audience and avoid using low-contrast colors for toggle states, or colors that might be confusing (such as red, which is associated with stop signs). Toggle is a great choice for providing clear, visible communication of the state of an element and its impact on the user experience.

Savvy teams consider the inventory of feature toggles in their codebase to have a cost and seek to keep it as low as possible. They will often add a task to their backlogs to remove obsolete toggles. Others will put “expiration dates” on their toggles and have a process in place that will fail a build or even refuse to launch an application if the feature is still enabled after the date passes.