The word toggle is most often used to describe a switch that can only have two positions: on or off. It can also be used as a verb, to mean “switch or alternate.” For example, you might toggle between the camera view on your phone or tablet so that you can see two friends at once on a video call.
In software, toggles are often used to allow users to change preferences or settings, like turning off Airplane Mode on your phone. They are preferred over radio buttons in mobile devices because they take less screen space and deliver immediate results. In contrast, radio buttons require the user to click a Save or Confirm button before changes are applied.
When designing a toggle control it is important to consider the context in which it will be used, as well as how easy it will be for users to understand its current state. This includes the use of color, which can have a profound impact on how intuitive a design is. For instance, using the color red for an on/off switch may be counterintuitive to audiences who associate it with stop signs or traffic lights. It is also important to evaluate societal and cultural contexts when choosing colors for toggle controls, as they can be used to convey meaning in different ways across cultures.
Savvy teams recognize that every toggle in their codebase comes with a carrying cost and aim to keep it as low as possible. This requires teams to be proactive about removing toggles that are no longer needed, both for performance and product-centric reasons. Some teams have a policy of adding a toggle removal task to their backlog for each new release, while others put “expiration dates” on their toggles which will fail a test (or even prevent an application from starting) if the flag is not removed by its expiration date.