Toggle is a simple user interface component that allows users to change preferences, settings and other types of information. They can be particularly useful on mobile where they take up less screen space than two radio buttons and enable users to toggle back and forth between the different states of a feature. When used well, toggles can improve user experience and help reduce the cognitive load of updating a setting or preference.

As with any type of user interface element, it is important to be thoughtful about when to use toggles and how to configure them so that they deliver the most value for users. In particular, we should avoid using low contrast colors as state indicators and be mindful of societal and cultural differences when choosing what words to use for states (On and Off). It is also a good idea to include clear labels and/or a short description next to the toggle that explains its purpose and how it works.

Toggle configuration can be managed in a variety of ways, but once a system reaches a certain scale it is often best to move it out of static files and into some sort of centralized storage, typically an existing application DB. This can dramatically decrease the time required to modify the toggle configuration and ensure consistency across a fleet of servers. In addition, it can make debugging easier by removing the need to re-deploy a toggle configuration artifact into a testing environment.