The toggle is a control that quickly switches between two possible states. It’s commonly used for “on/off” switches, but it can also be used to enact binary actions that occur immediately after the user flips the switch—such as displaying additional content or closing a form.

Toggles are often used alongside a label, and the labels should clearly describe what state the toggle is currently in. This allows users to understand which options are available to them and what the effect of their action will be. Toggle switches look like sliders and use visual cues to help differentiate them from other controls.

It’s important that developers take the time to write clear toggle labels. They should describe what option the toggle is controlling, and if possible, make it clear whether it’s on or off. It’s also important to write short and direct labels. A toggle is often a quick switch, so it should be easy for users to scan and recognize its current state.

Using toggle configuration as a feature flag can be a great way to allow teams to dynamically change their product’s behavior. However, it can be confusing if it is not carefully managed, and many teams choose to move beyond the use of static files and instead build out some form of centralized toggle configuration management — often in a dedicated application DB or existing application backend. This can make it easier for both automated tests and manual exploratory testing to view, modify, and test feature toggles.