In everyday technology, toggles are used to control features like WiFi and Bluetooth. When used in programming, they are a powerful tool for enabling/disabling codepaths and delivering different versions of a feature to users in an A/B testing fashion.

In web design, toggles are often used to control responsive layouts based on screen size or device type. They can also be used to dynamically show/hide navigation menus and sidebars based on the device that is being used to view the website.

While there are a number of different ways that we can implement toggles in a webpage, it is important to understand that they are not always the best option. In some cases, toggles can be confusing to the user, and in other instances they may be better replaced with a button. This is especially true if the toggle needs to be clicked for changes to take effect.

One of the biggest challenges when using toggles is knowing how to manage their state. While there are some limiting factors (such as the amount of time that the user can observe the toggle before it flips) it is generally possible to provide clear and consistent feedback to users to let them know what state the toggle is in.

This can be done in a variety of ways, from a simple “active” or “inactive” label on the toggle itself to a simple on/off icon on the page. In general it is recommended to use as few UI elements as possible to avoid confusion. However, the toggle is a useful tool for providing users with clear feedback, and it should be used judiciously.

Toggles are also a key component in newer agile development models, where they allow developers to hide new features while they are in the process of writing and testing them. Previously these features would need to be written on separate branches and then merged into trunk code, which can be a cumbersome process for teams working on tight delivery schedules. With toggles, these features can be kept in a release branch, hidden behind a release toggle until they are ready for release and market testing.

Once a release is approved, the toggle can be flipped to activate the new feature in production. This can be done through a variety of methods, from simple commenting to using the preprocessor’s #ifdef functionality. The most sophisticated options will include a centralized store for managing feature flags and their configuration, usually an existing application DB. These approaches are able to support more dynamic re-configuration of toggles, but they can still be quite difficult to maintain and manage in a large environment. Ultimately they are better used in smaller environments where the need for more complex re-configuration is limited.