A toggle is a switch that provides the ability to change between two states or options. It is a common feature found in everyday technology, computing, and programming to allow users the ability to switch between settings. Toggle switches can be flipped from one state to the other based on input or user interaction. A toggle can be used for many purposes in application development including to perform multivariate or A/B testing, or to make data-driven optimizations like changing Call To Action wording on a button.

When used properly, a toggle allows teams to rapidly deploy and test new features before they go live. It is more efficient than more traditional waterfall development models where developers must create and test new code on separate branches before it can be merged into trunk code.

However, it is important to keep in mind that the use of toggles can also introduce technical debt if the feature flag configuration becomes too complex or if the toggles are left unattended for too long. To help mitigate this it is important to have a process for regularly reviewing the existing toggle configuration and pruning those that are no longer necessary. Ideally this can be integrated into your feature flag management platform.

Toggle configuration typically takes the form of a Boolean variable. It is recommended that you have some type of centralized configuration repository to ensure consistency across systems and reduce the effort it takes to modify the toggles when necessary.