A toggle (often abbreviated T) is a type of switch that can either be on or off. It’s found in both hardware and software, for example, the caps lock or num lock keys on a keyboard are toggles that turn specific functions on and off. Toggles are also common in software when there are options or preferences.
The word originated in the 18th century for a pin passed through the eye of a rope to fasten it, but now we use it in a variety of ways. Often it’s used for an up-and-down command, such as turning on and off something like a light or television, but it can also be applied to more abstract concepts like switching between different settings, programs, or viewpoints. For instance, we can toggle between a portrait of someone and their landscape photo on Facebook.
In the context of user interface design, toggles are useful because they provide a quick way to update preferences or settings. However, they can be confusing if their current state isn’t obvious. To avoid confusion, toggle switches should have clear labels and standard visual cues, such as movement and color. The goal is to make it easy for users to understand what they’re choosing and why.
Users often misunderstand toggles when the colors of their active and inactive states don’t match up. Fortunately, this is easy to fix by using contrasting colors or making the toggle inactive when it’s already on. We tested four toggles in a study with varying color contrast and found that the ones with the largest contrast performed best when compared to the ones with the smallest difference. The reason for this is that the larger difference helps users quickly discern which one to select.
Another issue with toggles is that they’re often inaccessible to users who rely on assistive technologies. It’s common for web developers to copy toggle code off the internet and not take into account how screen readers and other assistive technologies interpret them. This can lead to features that aren’t activated or even presentable for users with disabilities.
The last issue to consider when designing a toggle is how the feature will be managed. Ideally, a toggle should be a temporary flag that will be rolled out and then reverted in a short time. But if a toggle needs to be more permanent, there are still plenty of ways to manage it without requiring a major release: A Canary Release, Champagne Brunch, or a private beta are all good options for managing a toggle that will stay around for longer. In any case, it’s essential to have a clear process for managing toggle configuration and making sure that it lives side by side with the rest of the source code so that we can easily roll out re-configurations in future releases.
