A toggle is a switch that allows people to choose between a pair of opposing states, like on and off. It typically uses a different appearance to communicate each state. Toggles are used in a variety of user interfaces, including web pages and native apps. When used consistently, they can reduce cognitive load for users. However, they should only be applied to settings, views, and content that can easily be updated by the user. When used for other kinds of data, toggles can lead to confusion and mistrust among users. Toggle switches should always be clearly labeled and deliver immediate effects. They should also provide feedback that makes it clear when their current state has been changed. Ideally, they should be positioned in the middle of the screen to avoid conflict with other controls, such as radio buttons or checkboxes.
A common example is an “Edit this review” feature in online reviews. This allows business owners to change the text displayed about their rating or remove it altogether. This can be confusing for customers, especially when the original text is removed and replaced with a new one. Google advises businesses to use this feature only if they are confident their customers understand the reason behind it, and that they have full control over the ratings on their listing.
Another way that toggles are often used is to hide content in article previews and other page elements. This can be useful when a business wants to test the impact of a particular change before making it permanent. This is very similar to the way that Facebook hides posts in its newsfeed, or the way that Apple hides app download links in its app store.
The word toggle comes from the 18th century term for a pin passed through the eye of a rope to hold it in place. The same principle can apply to software development: a toggle allows developers to temporarily leave code in an inactive state while they are working on it, then flip the switch to activate it for release. This supports more agile development processes than traditional waterfall models, where teams would create separate code branches for each feature they were working on.
Toggles can be based on a wide range of conditions, from fitness tests or other features in the codebase, to a setting in your feature management tool or a parameter in your config file. A toggle can even be a decision tree that evaluates the results of multiple conditions and branches, or a complex conditional logic engine. In these cases, they are commonly referred to as feature flags, although that is technically an incorrect term, since they usually live for a few days or weeks or are semi-permanent. The term feature toggle is generally reserved for long-lived or permanent flags.
