Toggle is a term used to describe an on-off control, such as the Caps Lock or Num Lock keys on a keyboard. This concept also applies to software, where toggles are often found in options menus for various functions such as privacy or settings.

A toggle is a simple, powerful user interface element that provides the ability to change a setting or functionality for all users of an application at once. The key to a successful toggle is clear, direct labeling that conveys the purpose of the switch, and a standard visual design. If implemented properly, toggles can make a big impact on the user experience and increase conversion.

Using toggles can be a great way to test new features in production without risking the experience of your entire user base. For example, if your engineering team wants to test a new feature with a small group of internal users before making it live for all, you can create a toggle that buckets those users into two different groups. When the toggle is set to ON, these users will see the version of the app with the new feature, and when it’s toggled OFF, they will see the original version of the app.

While toggles are easy to use, they do have some cognitive drawbacks — particularly for people with accessibility needs. In particular, a toggle that uses only colors to signal status can be confusing for users who have red/green color blindness. This is why it’s important to follow WCAG guidelines and use other alternatives that don’t rely on color alone to convey information.