A toggle is a switch that can be flipped between two states or options. It is commonly used in technology, computing and programming to allow users to change settings or modes based on their preferences.

When used correctly, a toggle is a great solution for responsive design as it enforces a mutually exclusive state (on or off). They are also ideal for mobile applications where users may want to change system functionality or settings. In these cases a toggle is preferable to a checkbox or radio button since it takes less screen real estate and does not require that a user click a Save or Confirm button for the changes to take effect.

It is important to avoid overusing toggles, especially in a single user interface. This can be confusing for the user and cause cognitive overload. Toggle buttons should be clearly labeled and their current state should be obvious to the user from context. It is important to not rely on color alone to convey this information, as per WCAG best practices.

Toggle configuration can be managed in a variety of ways ranging from static files to more complex and dynamic approaches. When using a static file approach it is important to name the toggle in a meaningful way that will help other developers quickly understand its purpose and meaning (or at least where it came from). A good practice is to use a preprocessor’s #ifdef feature when hardcoding toggle configuration so that it can be changed easily without re-deploying code (for less dynamic flags at least). For more complex approaches it is often necessary to build out some form of admin UI to manage Toggle Configuration.