A toggle is a button that has two opposing states (either on or off). It’s often used in technology, computing, and programming to allow users to switch between different settings or options. It’s the preferred control when changing system configuration on mobile devices, as it takes up less space than a checkbox.

When designing a toggle, keep in mind that it can be difficult for some users to discern the status of the switch when colors are not used. Use high-contrast colors for both the on and off states to help reduce visual noise. In addition, consider the societal and cultural implications of your color choices. For example, using red for the on position may be confusing to some users who associate it with stop signs or traffic lights. Toggle switches should also always include state descriptors to further clarify what they do.

Some dev teams choose to use feature toggles to support agile development processes. This way they can hide features while their teams work on them on code branches without having to wait for a longer testing and QA process before those features can be integrated into trunk code. This approach is often called a Champagne Brunch or Canary Release.

Feature toggles can also be used to perform A/B testing. By enabling and disabling different codepaths for each user cohort, they can determine which is the more effective version of their feature. This type of test is often called a Permissioning Toggle or Champagne Brunch.