Toggle is a control that allows users to set or reset the state of something, often in response to a change in circumstance. It’s the right control to use when your goal is to allow people to manage system settings or preferences (i.e states of functionalities). It’s also the preferred method for adjusting settings on mobile because it takes less screen estate in comparison with two radio buttons.
A toggle can be positioned either horizontally or vertically, and is usually colored red or black to distinguish it from the surrounding background. The red/black color scheme is a visual signifier that is familiar to most people, and can serve as a clear, intuitive signal to users about the current state of the toggle.
The most important design consideration when designing a toggle is to make it easy for users to understand its purpose. Labels are critical, and should describe the action that will be performed when the switch is ON or OFF, and also what state it is currently in. For example, “Airplane Mode ON” and “Average Price ON” are clear, direct, and concise labels.
Another key consideration is that toggles should be designed to feel tactile, as they would in the real world. This can be accomplished by making them physically large and using color to signify their current state. Additionally, utilizing visual cues like movement and/or sound can be helpful in providing a more realistic experience for users.
For more advanced configuration options, you can also use a toggle to implement a feature flag. In a typical implementation of this strategy, the toggle configuration lives side-by-side with the codebase in source control, and a special “feature flag router” is used to deploy the toggle at runtime. The router then consistently sends each user down one of the toggle’s configured codepaths. This enables you to perform multivariate or A/B testing on your product without having to restart the entire production deployment every time you want to try out a new experiment.
A toggle is also a good choice when you need to support multiple paths through the same functionality, but want to limit the number of clicks required for a user to exercise each path. For example, a toggle can be used to select between a stream and map view in a video player, or to choose between three different cameras in an aquarium exhibit.
Savvy teams consider the inventory of toggles in their codebase to come with a carrying cost, and aim to keep it as low as possible. This can be achieved by adding toggle removal tasks to the team’s backlog when a new Release Toggle is first deployed, and by building a process into their management platform that will trigger the deletion of idle feature flags at regular intervals. Some teams even go as far as to include expiration dates on their toggles to prevent them from hanging around after they’ve lost usefulness.
