A toggle switch is a control that enforces an either/or state of function (either ON or OFF). It can be more effective than a radio button because it takes less screen space. It is best used when you need to change system settings or preferences. It is also commonly used when you need a user to indicate something (either yes or no).
You should avoid using a toggle switch when the system needs to apply a new state immediately or without further confirmation. For example, it’s better to use a checkbox than a toggle switch in long forms or when users need to confirm the changes they have made before moving on. If there is any delay in the application of a toggle’s new state (such as an internet connection slowing down) it’s best to have a brief animation showing the process status, instead of simply waiting for the toggle to be updated.
While toggles are an excellent choice for a variety of situations, it is important to understand the cognitive limitations of this kind of control. They do not allow you to convey a third state (“doesn’t matter”) and are not as readable as a radio button. In addition, a toggle can be confusing to users if they press it multiple times in a row and see that the toggle doesn’t change its state.
Toggle is a sharp tool and can cause problems when used incorrectly. It’s important to always have a good reason for using a toggle, and to test any changes to ensure that they work as intended.
Often toggles are used for experimentation or A/B testing. This technique is popular in ecommerce and can be applied to anything from the purchase flow of a product to the wording of a Call To Action. In these cases a toggle is added to a production application and each user of the application is sent down one codepath or another, with aggregate data collected over time revealing which path performs the best. Once this information is available the toggle can be removed and the winning codepath goes live for all users.
Many teams use toggles to support agile development and release cycles. Features can be developed on separate code branches, then hidden behind toggles until they are ready for release. This way users can be given the opportunity to try out new functionality with minimal disruption.
Toggle configuration is typically stored in some sort of centralized store, often an existing application DB. This makes it easy for system operators, testers and product managers to view and modify toggle flags. This approach can become cumbersome if there is a lot of toggles, or if the toggles are configured in complicated ways, however it is still often easier than relying on static files to manage configuration.
