Toggle is a simple user-interface element that lets visitors update preferences or other settings. When used correctly it is a powerful tool for improving the overall usability of your site or app. Toggles should be clearly labeled and use visual cues to convey state — i.e. on/off, up/down etc. Toggle switches should be positioned in a predictable way and always provide an immediate result. They should also be consistent in appearance, ideally appearing as sliders that move to reflect state changes.

The word toggle comes from the 18th century definition of a pin or rod passed transversely through a loop in a rope, eye in a chain, or frog to fasten it: (see toggle joint). Today, we mostly use the term as a type of switch that alternates between two functions: on/off or up/down.

Release Toggles are short lived compared to other categories of Feature Toggles. They are typically flipped by rolling out a new release and shouldn’t remain in place for long periods of time unless they are being managed to meet business goals or are product-centric.

Experiment Toggles are a powerful technique for performing multivariate testing. They are based upon the Toggle Router which consistently sends a given user down one codepath or the other based on their cohort membership. They are also commonly used to make data-driven optimizations to existing features. When using this type of toggle it is important to have a centralized system for managing configuration and testing. Often this takes the form of some form of commenting or using the preprocessor’s #ifdef feature, but as these approaches don’t allow for dynamic in-memory re-configuration they are only suitable for a small subset of Use Cases.