The word toggle is most often used to describe a switch that has two positions, either on or off. It can also be a verb that means “switch or alternate,” as in the way you might toggle between screens as you video chat with two friends at once. In software development, toggles are used to control features or configurations that can be enabled or disabled. Toggles are generally favored over radio buttons because they can take up less screen space and do not have a pre-selected default state. However, toggles should only be employed where a user can clearly and consistently make a choice between ON or OFF and when there are clear visual cues (like animation or color changes) that signal the toggle’s new state. For example, it is inappropriate to use a toggle for downloading content because downloads are usually one-time events and turning on the toggle does not automatically turn off the downloaded content.
Feature Toggles are a powerful tool that enable teams to test and deploy new functionality without having to commit code to a production release or risk a downstream impact on other teams’ work. Toggle states can be determined by a wide variety of conditions including fitness test results, setting in a version management system or config file, or by a simple “if” statement that evaluates a number of different variables. Some savvy teams have rules that add a task to the backlog for removing a toggle once it has served its purpose, and some even put expiration dates on their toggles so that they will fail a test if left un-updated after a certain date.
Collapsible toggles can be an effective means of structuring article content. They minimize scrolling and can help readers focus on the content that is most relevant to them. However, if a visitor needs to access all the content on an article then it is a better alternative to use a navigation element like a sidebar or Table of Contents.
A toggle can also be used to perform A/B testing with an aggregation of data from users in a cohort. Toggle routers can be configured to consistently send users down one or the other code path and then aggregate and analyze the resulting metrics. This allows us to find and optimize things such as the purchase flow of an ecommerce site, or even the Call To Action wording on a button.
Toggles should be applied with care to avoid a confusing or misleading interface for users. When possible, toggles should be visible by default and they should have a distinctive icon that is immediately identifiable. For example, a toggle that controls a video or audio stream should have a distinctive play/pause or stop icon. Toggles should not be used in places where users need to click a Save or Confirm button for changes to take effect, such as long forms or confirmation dialogs. For example, it is inappropriate to use an ON or OFF toggle to indicate whether an account has been suspended because the user should be able to tell this from their account history.
