Toggle is a user-interface element that lets people update preferences, settings or other types of information. When used well, toggles have the potential to improve user experience by providing a simple and effective way for people to decide between two opposing states. Toggles should always have clear labels, be visually distinct, deliver immediate results and provide a clear indication of their current state.

Toggles should also be accessible for people with disabilities and cognitive issues. In particular it’s important to avoid using color as a signal of state because it can be misleading for some users. For example, using red for the on position can be confusing for users who associate it with stop signs and traffic lights. It’s also essential to consider societal and cultural context when deciding on color schemes for toggles.

Another good use of toggles is in testing and QA. For example, if a team is planning to change the default behavior of a feature it can be useful to use a toggle to test the impact of that change on a group of users. It’s then possible to switch the toggle back and forth between the existing and new default behaviors and see how each impacts the group of testers.

Toggles can also be used to perform multivariate and A/B testing. For this purpose they are typically used to manage Permission Toggles allowing us to dynamically send different cohorts down one or the other codepath at runtime.