A toggle is a switch that can be flipped on and off. It can be found in both hardware and software. For example, the Caps Lock and Num Lock keys on a keyboard are toggles that allow you to turn specific functions on or off. In software, toggles are used in almost every type of options menu that allows you to change an option item’s state. Toggles are a great way to quickly change settings and preferences without impacting the core functionality of your site or app. To make the most of your toggles, be sure to use direct labels and standard visual design to deliver immediate results.
The word toggle can also be used as a verb meaning to shift back and forth, as when you toggle a camera between landscape and portrait mode. The word may also refer to a piece of jewelry, such as a toggle chain or ring. It may also refer to the action of moving a pin or bolt across an eye or loop in a chain or rope to fasten it, or the act of changing from one mode of operation or setting to another.
Toggles are a very useful tool for managing feature flags and can be used to enable or disable features for different cohorts of users. They are very useful for testing new features before making them available to a larger audience. A popular use of Toggles is in the form of Experiment Toggles which are used to perform multivariate or A/B testing. By exposing different cohorts to different codepaths the team can measure which path has the most success and then implement it permanently.
While the use of Toggles can help teams manage feature flags it is important to remember that these toggle configurations are transitory by nature and will likely need to be changed often. Savvy teams will have a process for reviewing their toggle inventory and actively seeking out and removing toggles that are no longer needed. Some teams will even put “expiration dates” on their toggles so that they will automatically be removed from production when the time comes.
If your toggles are not being managed via a true distributed configuration system it is easy to end up with a situation where you have a mix of Canary Release and Champagne Brunch Toggles all mixed together in your production environment. This can be very difficult to debug if something is unexpectedly causing an issue. To avoid this problem consider building a system that supports the dynamic re-configuration of your feature flags at runtime, rather than having to deploy a full version of your app and manually flip a toggle for each test.
