Feature toggles are powerful tools that enable developers to release new features quickly, gain real-time user feedback, and pave the way for continuous improvement. However, they can be challenging to manage properly. Ultimately, implementing best practices and taking proactive measures can help reduce the risk of complex issues and ensure success.

The word toggle means a switch that has two positions, either on or off. In software engineering, it’s a similar concept—a feature toggle is a point in the code where execution branches in one direction or another. Toggles are a popular choice for enabling A/B testing, multivariate tests, and other optimizations because they allow development teams to run experiments on a live product without having to worry about the impact on other customers or negatively impacting revenue.

A toggle can be set to a specific state by using an identifier and updating the code to reflect that. The identifier and the toggle’s current state are then communicated to external systems such as Split and Optimizely. The feature toggle can then be activated or disabled based on the results of the experiment and the data collected.

Although it’s possible to hardcode toggle configuration, doing so can introduce significant complexity into the codebase and limit its ability to re-configure at runtime. Instead, it’s generally recommended to use a dedicated feature flag management tool such as Split to provide a robust and performant toggle platform.

When implemented well, toggles can significantly improve the speed and agility of your software development process. They eliminate the need for multiple feature branches that must be merged and reconciled on Github, and they also prevent active features from being accidentally enabled or disabled. In addition, they can be used to support the trunk development process, which enables teams to collaborate and release new features more quickly.

A toggle can also be a great tool for optimizing the user experience and ensuring that your web app is compliant with WCAG standards. For example, a toggle can be used to change the default text color for button labels and to disable the checkbox or radio button styles that rely on solely on color to convey meaning.