A toggle is a switch or button that can be pressed or clicked to allow users to change between two states or options. They are commonly used in technology, computing, programming and software applications to enable or disable features, switch between different display modes and other settings. Toggles are also found in everyday technology such as the Caps Lock and Num Lock keys on keyboards, and in most options menus for software applications.

Feature Toggles (also called feature flags) are a way to turn code paths on and off for certain groups of users within your software program. They can be configured based on a variety of factors including fitness test results, setting in your feature management tool, a simple “if” statement or even a complex decision tree which takes in a number of criteria. Typically toggles are transitionary in nature, but they can also live side by side with the code they control and can be changed as a part of a new release.

Be careful when deploying toggles, and try to keep them limited in scope. A large inventory of toggles can be confusing for users and can become a huge maintenance overhead for the team. Also, be sure to prune your toggles as soon as they are no longer needed. This can be done by adding a task to your team’s backlog or building the process into your feature management tool. Finally, avoid using color as the primary cue to convey a toggle’s active state — this has been shown to be unreliable at communicating meaning in user testing. A bold-thin combination is usually more effective.