Toggle is a simple user interface element, but when it’s not used well it can be confusing and frustrating. Especially when users have to rely on color and other visual cues to understand which state the toggle is in. It’s important to understand the cognitive issues associated with using toggles so that you can design them more effectively.

A toggle is a switch with two positions, on and off, that can be used to alternate between them. It’s a common interface element that is commonly found on mobile phones and computers and can be used to switch between programs or settings, for example enabling or disabling streaming video or changing the screen resolution. Toggles are also frequently used as a way to present options or alternative views for content on web pages, for example collapsible accordions and tabbed content.

Creating and managing toggles can be difficult, particularly at scale. Many organizations move their toggle configuration away from static files into a centralized store which is more easily managed by administrators and testers. This often accompanies a build-out of some type of admin UI which allows users to view and modify their toggle configuration.

When creating toggles it is important to provide clear labels that clearly indicate which option the toggle will activate, and what state the toggle is in right now. The use of high contrast colors for on and off states can be helpful in making the toggles easier to see, but it’s also important to consider the societal and cultural context of your audience when choosing color. For instance, red might be an inappropriate choice for a toggle label because many people associate the color with stop signs and traffic signals.

Toggles are often used as part of a canary release or canary deployment process in order to allow developers to release features to small groups of users and then roll them back if necessary without impacting the wider user base. This can be particularly useful when testing features for security or performance issues.

Some teams have rules in place to ensure that they are proactive in removing toggles from their codebase. Others have gone as far as to create “time bombs” which will cause an application to fail if it attempts to start up with an expired feature flag.

Using toggles as part of an experiment is called an Experiment Toggle. In an experiment Toggle a user is placed into one of several cohorts and at runtime the experiment will toggle the codepath for that cohort between two different paths, depending upon the aggregate behavior of that group. This is an efficient method for conducting A/B tests and can be much faster than implementing multiple variations of a page and tracking user behavior to determine which variation performs best. An Experiment Toggle can also be used to run multivariate tests, which is more powerful than simply running a single variant of a page against all users.