Toggle is an on/off switch that lets users change preferences, settings, or other types of information. They’re often found on forms, but they’re also sometimes used in non-formal interfaces like chats and text fields. When designers use toggle switches, they need to be careful that they provide clear, direct labels, stick with standard visual design, and deliver immediate results. Otherwise they may confuse users, leading them to misinterpret the toggle’s current state and causing frustration.

Toggles are commonly used to manage feature flags and for experimental UI optimization (also known as A/B testing). When a toggle is set to On it will enable existing or legacy behavior while when a toggle is set to Off it will disable that behavior. It’s important that teams have a good strategy around managing this configuration in their testing environments. For example many teams prefer to have the toggle configuration for their release live side by side with the source code in version control so that they can test a feature with the expected toggle configuration and a known fall-back toggle configuration.

In some cases though, it’s necessary for teams to dynamically re-configure specific service instances. To do this effectively they need to ensure that toggles that will be flipped in their release are flipped in testing before the release goes live. Alternatively they need to have a robust feature flag management system which allows them to perform runtime re-configuration for their toggles.