A toggle is a button or switch that allows users to change the state of a device or feature from one state to another. Toggles are especially well suited for adjusting settings or preferences that require a binary decision, such as turning Airplane Mode ON or OFF. For these types of settings, a toggle is usually preferable to a checkbox because it takes up less screen space and has a clearer default state.
A good toggle has a very clear and understandable label that explains what happens when the toggle is in its current state. Using high-contrast colors for the different states can help ensure that users see the toggle’s current state (On or Off). It’s also important to evaluate societal and cultural norms when choosing color, as some color choices can have unintended cognitive effects.
When managing feature flags at scale it’s common to move the toggle configuration out of static files and into a centralized place such as an existing application DB. This approach can make it easier for system operators, testers and product managers to view and modify the toggle configuration without redeploying the code.
Regardless of how the toggle configuration is managed it’s critical to be proactive about managing the inventory of toggles. Adding a toggle removal task on to the team’s backlog whenever a toggle is introduced can prevent teams from accidentally re-enabling old functionality. Some teams even go as far as to put expiration dates on their toggles and have the toggles fail a test if they have expired.