A toggle is a hardware or software switch that has two positions, on or off. Toggle switches are found everywhere from options menus to the keyboard’s Caps Lock and Num Lock keys. They are used in almost every application that provides some form of configuration, from setting the number of tabs displayed in a browser to enabling features like cookies. They can even be used to switch between screen resolutions when video chatting with friends.
Toggle is also an architectural term describing the way a rail or bolt fits into a larger hole in a building to hold a load bearing beam, door or window. The simplest toggle is made of metal bars or rods bent together, with one bar slipped into the larger hole and held tightly in place by another. The toggles are often connected to each other by a chain or rope to prevent them from falling out of the holes.
Unlike many software interfaces which require users to click a button for every action, toggle switches are easy to use and can be used with minimal space, making them ideal for applications that need a simple control with few options. In addition, toggles are a good fit for use in mobile devices where the small screen size limits available interface elements.
For these reasons, toggles have become ubiquitous in web applications. But despite their simplicity, there are some pitfalls to be aware of when designing and using them.
As with any user interface element, the way a toggle switch is designed and labeled can have a significant impact on its usability. When creating a toggle, make sure it is clearly visible to the user and that its labels are short and clear. Avoid using neutral or ambiguous words such as “on” or “off.” Instead, try to incorporate verbs to help clarify what is happening, such as:
The use of color can also be confusing for users. Be careful to use high contrast colors for toggles and consider societal and cultural contexts when selecting colors. For example, the color red might not be a good choice for a toggle label as it may cause confusion among users who associate it with stop signs and traffic lights.
Another common problem with toggles is that they are not typically well-designed to be accessible to people who use assistive technologies such as screen readers and Braille displays. When a toggle is simply a checkbox and does not move position or change in color it can be difficult for these users to tell whether it is active or inactive, especially if the toggle is on a dark background.
Managing feature toggles through static files can quickly become cumbersome at a certain scale and is not well-suited for dynamic re-configuration of a service instance in a test environment. For this reason, savvy teams tend to prefer some form of centralized toggle configuration, usually in an existing application DB and sometimes along with a dedicated admin UI for viewing and modifying Features Flags. This can make it much easier to quickly test new behaviors without having to manually re-deploy a service instance for each test case.
