A toggle is a button or switch that allows you to change between two different states or options. It is commonly used in everyday technology such as keyboards with Caps and Num Lock switches or the options menus of many software applications. Toggles are most often used for features that have only two outcomes: on or off.
Toggles are a valuable tool for your engineering team to use in their A/B testing practice. Using feature toggles to test new functionality with a segment of your users before deploying it to all your customers helps reduce the risk that you will roll out a new feature that isn’t well received by a large portion of your audience.
When creating a toggle it is important to clearly communicate the current state of your feature with its label and visual design. Providing direct labels that are consistent throughout your application and providing visual cues like color changes can help make the toggle easy for users to understand and interpret. Toggle switches should also be accessible to users with disabilities by utilizing alternative text for screen readers and visual cues that are visible to those using assistive technologies.
Managing toggle configuration is one of the most challenging aspects of developing an app that uses feature flags. The most basic approach to this is hardcoding toggles in the source code of an app which has its drawbacks including slowing down the overall CI/CD cycle and not supporting runtime re-configuration. Alternatively, some teams choose to manage their toggles in a separate file that is deployed into their testing environment. While this does improve the cycle time it still doesn’t support runtime re-configuration and therefore only really works well for very short lived toggles such as Champagne Brunches or Experiment Toggles.
