What Is a Toggle?

A toggle is a switch that can be in either of two positions, on or off. It’s a simple user interface component that is very useful in many situations. We can use toggles to let users update preferences, settings and other types of information. Toggles are often used in conjunction with other components such as dropdowns, checkboxes and radio buttons.

A great example of this is the ability to toggle the display of your sent messages in Gmail on and off. It’s a convenient way to keep track of what you’ve already shared without making it visible to everyone.

The word toggle is also a verb meaning to move back and forth between states, for instance when switching between a desktop and laptop monitor in a video conference. Toggle is also a common word in computer programming, referring to the process of changing an application’s state between on and off.

When using a toggle, it’s important to ensure that the current state is clear and well understood. Color can be a powerful visual cue to help users understand what state a toggle is in. For instance, designers often use a darker shade for the active toggle and a lighter color for the inactive one. But color alone isn’t enough to make a toggle intuitive. A number of users have color blindness, which can mean that a more pronounced color is actually lighter for them. In addition, the WCAG doesn’t recommend that we rely solely on color to convey a toggle’s state.

While hardcoding a toggle’s state into code is a good option for static flags, it becomes cumbersome at scale and doesn’t allow for dynamic re-configuration. Some teams choose to hardcode the toggle’s state into a source file through commenting or preprocessor features such as #ifdef. While this allows for re-configuration, it can be difficult to test and is only suitable for toggles that are unlikely to change over time.

Savvy teams view feature toggles as inventory with a carrying cost and are proactive in removing them when they are no longer needed. This can include adding a task to the team’s backlog for every toggle that is introduced, creating a checklist to review the list of toggles on each release and adding an expiration date for each of them. Some teams even go as far as to create a script to automatically fail a release if a toggle is still present at the time of deployment!

Toggle switches are a great tool for user control in applications that have lots of options. However, it’s important to remember that they can be confusing for some users, especially when they are not implemented consistently across the product. In order to avoid this, it’s recommended to provide clear labels, standard visual design and deliver immediate results.

Toggles are a great tool for performing A/B testing, which is the practice of sending users through different code paths based on their cohort. By running a series of experiments we can quickly determine which toggle switch is the most effective.