Feature toggles (also known as feature flags) enable teams to release, integrate and test features faster and more efficiently. They can be used to show/hide functionality, limit the audience of a feature, manage permissions or even check system load. Savvy teams use a variety of toggle types in their releases and make sure they have the proper checks in place to prevent unintended regressions or bugs.

When a toggle is on it must be set to one of its two states, either On or Off. Unlike a button which allows for more than two states, toggles enforce this mutually exclusive state. This helps to reduce complexity and user confusion in the interface. In contrast to a button which can be clicked multiple times, users will not be confused if toggles are pressed repeatedly in succession or if they are pushed on and then off again.

In addition, it is best to keep toggles as simple as possible in terms of their underlying logic and their visual appearance. Toggles should clearly identify the setting, view or content they affect and update their appearance based on their current state. This way people can quickly understand what effect a toggle will have and can avoid accidentally changing the state they are expecting to see.

The flexibility of toggles makes them an ideal tool for validating new functionality with a subset of your audience before it is fully rolled out. When a toggle is set to ON your whole audience will get the new feature while when it is set to OFF they will continue to see the original version of your product.