A toggle is a switch that has two positions: on and off. Toggle switches are commonly found on hardware such as phones, TVs and computers, but they are also used in software to enable different functionality. For example, a toggle can be used to alternate between two video chat screens during a call with friends at the same time. Often, toggles are marked with high contrast colors and a clear state descriptor (On and Off) to help users understand what function is enabled or disabled. When using toggles in software, it is best to limit the number of features that they control and only use them where their impact on user experience can be easily evaluated by a small sample size. This is important to prevent cognitive overload and ensure that toggles can be re-configured quickly.
A toggle can also be a powerful tool to conduct A/B tests. An ecommerce company, for example, might decide to test two different suggestion algorithms on their configurator. They would add an experiment toggle to their production system which buckets users into one cohort or the other when they load the configurator. Once the experiment is complete and the company is happy with the results they can remove the toggle to make the new algorithm live for all users.
Toggles are often the primary method for deploying code changes to a production environment and can help speed up development cycles and reduce technical debt. However, it is important to keep in mind that they can also be used to rollback features in the event of a crash or other failure. As such, it is vital to have a system in place that can detect and manage feature flag configurations so that these features can be safely rolled back.
