Toggle is a control that lets people switch between a pair of opposing states like on or off. When used correctly, toggles help users make informed choices and can be an effective substitute for radio buttons or checkboxes. However, when misused, toggles can introduce confusion and mistrust in the user experience. When designing a toggle, it’s important to consider how each choice will affect the user experience and what a person will see when they open the toggle. Toggle buttons do not display the text on or off and therefore rely on visual cues to communicate their state. Choosing these visual cues is not as simple as it sounds. For example, it’s common for designers to use colors to convey a toggle’s state but this can lead to cognitive problems for some users. Using a color to convey the toggle’s state can be confusing for people with color vision deficiency or who might associate the color red with things like stop signs or traffic lights. In addition, color can also have a lot of cultural associations which can cause issues in some cultures and audiences.

Savvy teams view Feature Toggles as inventory that comes with a carrying cost and seek to keep the number of toggles in their codebase to a minimum. For this reason, it’s critical to carefully test each toggle configuration before it goes live. Generally, this means testing the toggles that are expected to go live in production flipped On as well as any other toggles that you want to eventually roll out flipped Off. In addition, many teams also test a fallback configuration with all the expected toggles flipped Off to avoid surprise regressions in future releases.