A toggle is a piece of hardware or software that allows you to switch between two functions. For example, your computer’s Caps Lock and Num Lock keys are toggles for their specific functions. Likewise, you’ll find toggles in most options menus.

Toggles are a cognitively OK choice if they have direct labels that describe what will happen when they’re clicked. For example, they’re OK if the label clearly states “Cookies” or “No Cookies”. Despite being cognitively OK toggles can still be confusing to use due to their mutually exclusive states. They’re best used for things like updating preferences, settings or other information.

However, when used for something like changing a user’s cookie setting or disabling a feature, they can be dangerously confusing. This is because a toggle is a switch between two mutually exclusive states (on and off). If your product uses a toggle for a setting or feature that could be confusing then be sure to provide clear and direct labels for each of these states and use visual cues like movement and color to avoid confusion.

Savvy teams often test their releases with all toggles flipped on to verify that existing or legacy behavior is enabled with the new release. Additionally, they’ll often test a fallback configuration with all toggles flipped off to ensure that no surprise regressions make it into production. Some teams go so far as to place toggle removal tasks on their backlogs or even add expiration dates for their feature flags.