A toggle switch is a simple user interface element that allows people to choose between two opposing states. It usually has a different appearance in each state, and it can be used to change the state of a view or content item.

It’s important to use toggle switches sparingly, and only when they are appropriate for a particular situation. They can be visually confusing and may not always be the best choice for a specific task. In some cases, a button might be a better alternative. Toggles should always be clearly labeled, and they should be used to manage the state of a view or piece of content. They should not be used to control other types of actions, such as choosing from a list of items.

The most common problem with toggles is that they don’t always communicate their current state clearly enough to users. This can be because they lack a clear on/off indication, or because the visual cues they do use aren’t effective. For example, some designers use red as the on state for toggles, but this can be difficult to perceive for people with color vision deficiency.

Another issue with toggles is that they can have a high maintenance cost in the context of an application that relies on continuous integration and delivery (CI/CD). Toggle-based configuration is slow to change, and it can impact cycle times for testing and debugging. Savvy teams think of feature toggles as inventory with a carrying cost, and they strive to keep that inventory low. Some even go so far as to create “expiration dates” on their toggles, causing them to fail in tests if they are still active at the time of an automated test run.