A toggle is a control that lets people choose between two opposing states, such as on and off. It uses a different appearance for each state and provides visual cues to help users manage the switch’s state. Toggles are often used to make responsive designs more effective by allowing users to switch between different layouts or display options based on their screen size or device.
Unlike other controls, such as radio buttons or checkboxes, toggles do not contain the text “on/off” and require users to rely on other visual cues when reading them. However, using the right visual signals isn’t as easy as it sounds and if not done correctly, can lead to confusion and user frustration.
One of the most common ways that designers use toggles is to allow users to change the display theme for an app. For example, some macOS apps let users choose between light and dark themes so that they can customize their experience to suit their preferences for readability or aesthetics. While this is a great example of a toggle’s utility, it’s important to note that a toggle shouldn’t be used in this context without carefully considering the underlying user experience. Specifically, it’s critical to ensure that the toggle doesn’t introduce cognitive load into the interface, especially for users with accessibility needs.
Toggle configuration can be managed via static files, but once you get to a certain scale this becomes cumbersome and managing consistency across a fleet of servers can be challenging. For this reason many organizations opt to move toggle configuration into some type of centralized store, typically an existing application DB. This is generally accompanied by the build out of some type of admin UI that allows product managers, developers and testers to view and modify the feature flags and their configuration.
Another key practice is to name your toggles appropriately. This helps everyone on your team understand what each toggle does and why it was created. In addition it can help you track the history of a toggle so that you know when its lifecycle has expired and it should be pruned from the code base.
The best way to prevent old toggles from clogging up your codebase is to deploy them strategically and to keep their inventory low. Whenever you do decide to deploy a new toggle, it should be clearly visible and should have a short-lived lifecycle. For example, a feature toggle designed to test a canary release strategy should be deployed to a small cohort of users and then rolled back as soon as the experiment has been validated.
Likewise, a QA toggle designed to test specific conditions should be short-lived if it is not going to be rolled out to the rest of your user base. The last thing you want is for an old QA toggle to stick around and introduce bugs into production. For this reason it’s best to only deploy QA toggles in highly controlled scenarios.
