A toggle is a switch that allows you to turn something on or off. It is commonly used in everyday technology devices like smartphones to enable WiFi and Bluetooth or to switch between different display modes. In software applications toggles are used to enable or disable existing features as well as future ones.
A common use case for feature toggles is to provide a canary release of a new or improved user experience before rolling out the change broadly. This is a great way to mitigate the risk of releasing a product feature that doesn’t work as intended. The toggle can be turned off by the product team until it has been properly tested with a small cohort of users, and then can be switched back on to deploy the new feature. Using this approach avoids the need for code branches as would be required with more traditional waterfall development models, and allows teams to move quickly from feature ideation to delivery of the new functionality to users.
The ability to toggle between multiple configurations of a web page makes it a useful tool for creating responsive design solutions. For example, using a feature toggle to hide navigation menus or sidebars when a screen is smaller than a minimum width can improve the UX for mobile visitors by reducing visual clutter. The toggle can then be turned on again once the screen is larger than the minimum width to re-enable the hidden elements.
Many teams find that they use toggles to experiment with different user experiences before making a final decision about what should be released to users. For example, an e-commerce company might add two different suggestion algorithms to an online configurator and then run an A/B test with users on the difference in performance before deciding which algorithm to go live with. The results of the test can then be measured against a set of business metrics before the decision is made about which algorithm should be rolled out to all users.
Toggle switches are also a common way to create accordions and collapsible sections on a web page. This helps keep the layout of the page clean and provides an easy way for users to access the content they want without having to scroll excessively. For example, articles on Medium often use a visibility toggle at the top of each post to allow readers to see or hide article content based on their subscription level.
Toggle configuration can be managed using a variety of techniques ranging from simple but less dynamic approaches such as commenting through to more sophisticated options such as code modification and preprocessor flags. Savvy teams view their toggle configuration as inventory that comes with a carrying cost and seek to minimize the number of toggles they have in production at any given time. In order to reduce technical debt it’s recommended that teams regularly review the list of toggles and remove those that are no longer required.
