Toggle is a simple user interface control that lets a user update preferences, settings or other types of information. When used correctly toggle switches can help to improve user experience and reduce frustration. The key is to use the feature sparingly and ensure that any toggles are clearly labeled and designed with standard visual cues.

Savvy teams view Feature Toggles as inventory which comes with a carrying cost and seek to keep the number of toggles in their codebase low. To do this they are proactive in removing toggles that are no longer needed. Some teams have rules about always adding a toggle removal task to the backlog when a new toggle is introduced and some even put “expiration dates” on their toggles (e.g. if the toggle isn’t removed before an expiration date then the system will fail to start).

A toggle switch typically looks like a slider and uses visual cues to signal its state. For example, when a toggle switch is pushed to the on position it should be highlighted in a different color from the off state. This helps to ensure that a toggle is easily identifiable as being in the active state. It’s important to consider societal and cultural implications when choosing colors for toggle switches as not all audiences will associate the same meanings with the different color states.

A toggle is also a mechanism for performing experimentation and can be used to run A/B testing or other multivariate experiments. The idea is that a toggle can be set to consistently send a specific cohort of users down one code path or another. This is often done by creating a specific toggle route in the Toggle Router.