The word toggle originally meant “pin passed through the eye of a rope to secure it.” Today, it refers to any binary switch that controls either an option ON or an option OFF. You see them everywhere in software and hardware: the Caps Lock and Num Lock keys on a keyboard, for example; the options menus in many applications. The term is also used for any kind of up-and-down control that is always on or off, such as a light switch.

Toggles can be a good option for simple switches, especially when users can easily perceive the current state. This is especially true when the visual cues of the toggle are clear and don’t rely solely on color to distinguish states (like checkboxes and radio buttons do).

In addition, it’s important that the label makes clear what the toggle will do when it’s ON, as well as what state it’s in right now. This way, the user can make a decision quickly and with confidence.

Feature Toggles

Toggle-based feature flags are great for making data-driven optimizations to your product, but it’s important that you understand the limitations of this technique before using it in production. One common problem is that you’ll be forcing your team to re-deploy an artifact each time the toggle changes, and this will negatively impact the cycle times of the entire CI/CD pipeline. To avoid this issue consider exposing an endpoint that allows for dynamic in-memory re-configuration of a toggle.