A toggle is a user interface component that allows the user to update preferences, settings or other types of information. Toggles are useful for reducing the number of clicks required to make these kinds of changes. They also tend to be more responsive than checkboxes or radio buttons, making them a good choice for situations where users want to see their progress in real time. However, toggles can be problematic if they are not used correctly. They often have unclear labels and may confuse the user by relying on color to convey meaning. This can be a problem for people with certain color vision impairments, and should be avoided whenever possible.

Many teams use Feature Toggles to test new features in a controlled manner before they are fully deployed to all users. For example, when Facebook redesigned their news feed they first rolled it out to a small percentage of users via a Feature Toggle before fully deploying the change to everyone. This allowed them to collect feedback and make necessary adjustments before rolling out the feature to all users.

Creating Feature Toggles is a complex process that can be prone to mistakes. When a toggle is not created correctly or not removed when it’s no longer needed it can lead to confusion and even debugging problems in production. Savvy teams consider the inventory of Feature Toggles to be an asset that comes with a carrying cost and strive to keep that count low by being proactive about removing toggles as soon as they’re no longer needed.