How to Manage a Toggle in Software Development


A toggle is a small piece of wood or plastic that is sewn to something, such as a coat or bag, and pushed through a loop or hole in order to fasten it. The word can also be used to describe a switch that allows a user to alternate between two positions—for example, the way you toggle on and off screens when video chatting with two friends at once.

In software development, toggles can be used to manage features in a transitional or experimental state. They are most commonly implemented with either a dark and light state or an on/off state and they allow a developer to manage feature availability in a gradual way.

When designing a toggle it is important to consider the underlying technical infrastructure. Toggle configuration management can range from a simple commenting strategy to a more advanced approach using a preprocessor’s #ifdef feature or other dynamic re-configuration features. However, even these solutions can be cumbersome at scale and may require a certain level of discipline to manage.

The most common way to manage a toggle is by keeping the configuration in source control side-by-side with the code which it controls. This makes it easy to verify that a release is configured properly and reduces the amount of manual work required in validating a feature’s behavior. However, this solution can also lead to a maintenance burden as teams must actively manage the number of toggles they keep in production and test the impact of new or changed toggles on existing code. Savvy teams often adopt policies which include adding a toggle removal task to the team backlog and some even place “expiration dates” on their toggles so they can be automatically flipped off at a predetermined time in the future.