A toggle is a switch that can be either on or off. It’s found in almost every aspect of computing when you have options or settings that can be switched on or off. Often, toggles are used to update preferences or other types of information. Toggles should be clearly labeled and utilize visual design to deliver immediate results.
In computing, the word toggle can also describe switching back and forth between programs. For example, if you are video chatting with two people at once you may toggle between the screens of each conversation. The term can also be used in reference to a specific type of fastener, such as a toggle iron, that fastens rope or cord.
Toggles should be used sparingly and only when you need to provide users with a way to update preference or other information. It’s important that the toggle switches look like sliders and use visual cues (i.e. movement and color) to avoid confusion. Color is especially important to consider when designing toggles — be sure to think about contrast and cultural implications for your audience.
Many teams find it wise to test their feature toggle configurations on a regular basis. Ideally they will test the exact toggle configuration that will be live in production plus any toggles they intend to release flipped On. This helps to ensure that existing or legacy behavior is enabled when the toggle is On and new or future functionality is disabled.