A toggle is a switch that can be on or off. It’s found in almost every aspect of computing when there are options or preferences. It’s also a verb meaning to switch or alternate: the way you toggle between screens as you video chat with two friends at once.
Toggles are often used to allow users to update settings or preferences. They help users make decisions quickly and provide immediate results. However, they can be confusing if not designed and implemented properly. When using toggles, consider direct labels, standard visual design, and a consistent use of color to indicate state change. Also, be sure to evaluate societal and cultural context when choosing colors for states (e.g. red for on can be counterintuitive for users who associate it with stop signs or traffic signals).
Another issue with toggles is that they rely on the user to be able to click and move between the two different states. This is problematic for users who are blind or vision impaired. This is why it’s important for web designers to make their toggles fully accessible.
Another common use for toggles is to perform A/B testing. In these cases, a toggle router will be set up to send each user down one codepath or the other, depending on what cohort they are in. Savvy teams will regularly review their toggle inventory and remove or modify those that are no longer needed, either through manual backlog management or by using a feature flag system with runtime configuration.