Toggle is a common user interface element that allows people to update preferences, settings, and content. When designed well, toggles are clear, simple to understand, and deliver immediate results. They can be used to enable and disable features, or to display or hide information. Using them appropriately can improve accessibility and increase the clarity of an interface, but there are some cases where they may introduce cognitive problems for users. This article discusses some of the most common issues associated with toggles and offers advice on how to avoid them.

Toggles can be confusing to use when the design doesn’t clearly communicate their purpose. In addition to displaying an icon that communicates the toggle’s function, designers should consider whether there is any additional text that can help explain what the toggle is doing or the effect it will have. They should also evaluate the societal and cultural context in which their toggle is being used and avoid colors that have negative associations (such as red for off) or that are counterintuitive for the audience.

One of the most common issues with toggles is that they rely on visual cues alone to convey state. While this is fine in some situations – e.g. a checkbox that uses a dark background to indicate it’s active – it’s not in others. In an experiment where we tested four toggles that all had a similar difference in font size between the active and inactive states, we found that those with the smallest difference performed best. This is probably due to the fact that the change in appearance was so obvious that it caught the user’s attention before they had a chance to question it.

When it comes to using toggles to perform a/b testing or other types of experimentation it’s important to keep in mind that you should be using runtime configuration instead of static files. Trying to manually modify an existing toggle through static files can be very cumbersome and can affect a team’s ability to validate changes quickly. In some cases it may even require restarting the process you’re testing to re-flip a toggle. This can negatively impact the all important feedback loop that CI/CD provides.

To avoid this issue many teams prefer to use a toggle router that supports dynamically changing the current toggle configuration at runtime via an endpoint. This approach avoids the need to restart a process or re-deploy an artifact into a testing environment and can be particularly useful in complex environments where multiple teams are working on a single product. It’s also wise to ensure that your toggle router tests both the toggle configuration you expect to be live in production and a fallback configured with those toggles flipped Off. This will help prevent any unexpected regressions in future releases.