Toggle is a word that is often used to describe the action of switching between two possible states. This binary action is most often found in a switch (like the one on your keyboard that turns the Caps Lock or Num Lock functions on and off). However, it can also be found in software settings that let you toggle the visibility of certain elements or features.
Despite their simple appearance, toggles can have significant usability issues if not implemented correctly. A poor choice of color, lack of clear labels or confusing placement can lead to confusion and inconsistency. In general, it is best to avoid using toggles in situations where the user may need to update settings or preferences. Instead, use a standard form element such as a checkbox or radio button in those cases.
The good news is that many of these problems can be avoided with a little effort. A key consideration is to provide clear label text that clearly indicates what state the toggle is in and its current effect. It is also important to evaluate societal and cultural contexts when choosing colors for the toggle. Red, for example, can be difficult to distinguish in low-contrast settings and can have negative connotations in some cultures. Using a dark blue in these situations can be more effective.
Lastly, savvy teams try to limit the number of feature flags in their codebase and strive to make sure that only essential flags are left active. This is often achieved by implementing a feature flag management system that allows you to dynamically re-configure a toggle at runtime rather than having to change a static file in source control.