Toggle is a term used in both software and hardware for switches that have only two positions, on or off. They are found in options menus and similar features in most applications and on keyboards for the Caps lock and Num lock functions.

There are a few things to consider with toggles when designing them. It is important to remember that they can be confusing for users unless clearly labeled. The most common mistake is using low-contrast colors to indicate states – this is not a good idea. In addition, relying on color can be problematic for users with visual impairments. A good alternative is to use clear labels (either text or a graphic) to describe the state of a toggle switch.

For example, a visual depiction of a toggle switch that is currently on could be a checkmark in the middle of a circle with an arrow pointing to it indicating that it is active. In addition, a toggle switch that is currently off should have an arrow in the opposite direction indicating it is not active.

Toggle configuration can be managed in a variety of ways, ranging from static files to more sophisticated approaches using a preprocessor’s #ifdef feature or an existing application db. In general it is best to have the toggle configuration live side-by-side in source control so that it can be easily modified for testing and debugging. For larger scale deployments it is usually preferable to have a separate centralized system that allows product managers, engineers and testers to manage and modify Feature Toggles and their configuration.