Toggle is a software development tool that allows developers to quickly implement new features with limited impact on existing code. Often called feature flags or switchable options, toggles are a powerful way to streamline your release cycle, gather real-time user feedback and pave the way for continuous improvement.

Toggles can be used for almost anything that changes the state of content or a view (like hiding a vignette, hiding a map pin, collapsing an article section). They can also be used to make things invisible for users in order to test out changes before making them permanent.

A toggle can be based on any condition that can be easily checked in the codebase. This can be as simple as a fitness test result, a setting in your feature management system or even a variable provided by a config file.

One challenge with toggles is that they can drive up the number of database calls if they are frequently updated. This can have a significant negative impact on performance in production. To minimize this challenge, it is important to clean up toggles quickly and never have more than a handful of toggles active in your codebase at any time.

Another challenge with toggles is that they can be confusing to users if they are not designed well. It is important to make sure that toggles are clearly labeled to explain what they will do when flipped on. For example, many teams use a green and red color scheme to help users understand the state of a toggle. This can be very confusing for people who have red/green color blindness, so it is best to avoid this for accessibility reasons.