A toggle lets people choose between a pair of opposing states, like on and off, using a different appearance to indicate each state. You’ll see toggle buttons on many types of apps, from the virtual switches that control your computer’s screen brightness to the physical ones found on some cars and phones. Toggle switches are a powerful tool that can be used to perform a variety of tasks, from changing the background color of your web app to optimizing an online purchase flow for conversion. However, the choice of when and how to use them is not without risk—a poorly designed toggle can do more harm than good.
In the most common usage, “toggle” describes switching back and forth between settings or programs, such as turning on and off a flashlight during a camping trip. However, the word is also often used to describe other types of binary actions. For instance, a software developer might toggle between different code paths while debugging an application. In the context of product management, toggles are frequently used to implement multivariate (A/B) testing and similar techniques to make data-driven optimizations.
Toggles are often used to enable features for a certain segment of the user base, while allowing other segments to disable them. For example, an e-commerce company might add an experiment toggle to its production configurator that splits users into two cohorts. By running an A/B test with this toggle, the team can measure whether more users complete their orders with the A or B algorithm and then decide which one to deploy to all users.
For each toggle that goes live in production, it’s important to have a clear process for vetting whether it’s the best way to solve a given problem. If a toggle is not appropriately scoped, it can be difficult for other teams to understand how to interact with the feature and can become a thorn in the side of agile development processes.
The most important consideration when designing toggles is to always write clearly labeled switches that tell people what they’re switching between and how each switch’s current state affects the user experience. This includes making the switch’s visual state clearly communicate what the action is, such as displaying a checkmark for “on” or a cross for “off.”
It’s also important to ensure that the toggle is accessible for all users, including those with red/green color vision deficiency. Toggle switches can be confusing to these users if they use a red/green color scheme—for example, some automobile manufacturers use red and green to indicate whether the headlights are on or off.
