A toggle is a switch or button that can be pushed to change between two states. This functionality is often used in technology, computing and programming to allow users to change settings and options in a seamless way. Toggle can also refer to a physical switch found in electronics like computers and laptops that allow users to switch between different functions using the same button or key.

Feature toggles are an important part of many teams’ continuous development practice. By allowing teams to test new functionality with a small group of their audience before it’s fully rolled out, toggles help reduce the risk that a new feature will be negatively received by the entire user base. They can also act as circuit breakers when a feature isn’t ready for production, preventing a product from getting released if it doesn’t meet quality or performance requirements.

There are a number of things to consider when designing and developing a toggle, including the following:

It’s important that a toggle is easily understood by its audience. A good way to achieve this is through clear and concise labeling that describes what the toggle does in a clear way. It’s also helpful to include an icon next to the toggle to further clarify its purpose. Finally, it’s important to design a toggle that provides a sense of consistency with the rest of your product and app. This can be achieved through consistent color, animation or other visual cues that signal a toggle’s state changes.

Toggles should always be accompanied by a descriptive label that answers the question, “What does this toggle do?” It’s best to use action-oriented labels that have a binary answer. Moreover, it’s important to give each toggle a unique name to make it easier for someone on your team to find it and understand its meaning.

A toggle is often used in conjunction with other features to create an experimental environment. For example, you can add an experiment toggle to your configuration tool that allows a cohort of users to try out two different algorithm options. Once your team has conclusive data that one of the options is performing better, you can then switch the default for all users to that option.

Toggle configurations can be complex, but they should always be testable. It’s best to test any toggle that you expect to go live in production with all of its configurations flipped on, and to also test it with all of its configurations flipped off. This way if you do encounter regression bugs, you’ll have the option to roll back to the previous release version.