A toggle is a button or switch that can be used to switch between two opposing states or options. Toggles are often used in technology, computing, programming, and communications to allow users to update settings or modes.
When it comes to user interfaces, toggles are useful because they allow the developer to present a different version of an application to users. This allows engineers to perform multivariate tests or A/B testing by bucketing users into two groups. When a toggle is switched ON users will see the new version of the application that the engineer is testing, and when it is turned OFF users will see the original untested version of the application.
Toggles are also useful because they can be implemented in a way that is very visible to the end user. By providing direct labels and using standard visual design, toggles can make a big difference in how easily and effectively your users can navigate your website or app.
However, it is important to remember that toggles are a relatively powerful tool that should be used sparingly. Too many toggles in a codebase can be confusing for the rest of your team and a pain to debug weeks or months down the road when they are turned off in production. To avoid this risk, it’s best to keep your inventory of feature toggles low and always use a good naming convention so that people on your team can understand the purpose of each toggle when they see it in error messages.