What Is a Toggle?

A toggle is a hardware or software switch that can be set to one of two states: ON or OFF. In software applications, toggles are often used to turn features on or off, or switch between different display modes. Toggles are also a useful tool when implementing responsive web design, as they allow developers to control the visibility of specific navigation or display options based on a user’s device or screen size.

A feature toggle is a way to deploy new code changes in small increments so that engineers can test them in the real world without impacting users and production stability. Because they’re a central part of your deployment process, feature toggles make it easier to roll out or roll back code and improve your application’s MTTR.

Whether your team is using a trunk-based development approach or a more agile continuous delivery model, feature toggles help you avoid costly mistakes by allowing engineers to commit changes to the main branch of your source code management system while keeping the existing functionality running in parallel. They can even serve as a central way to remotely control certain elements in your application during high latency periods, like a server-side crash.

Toggle switches are commonly used in everyday technology devices and apps, such as smartphones and computers. They can be found in settings or programs such as Microsoft Excel and the Windows calculator, where they can be used to enable or disable specific functions. They are also commonly used in software applications, where they can be configured to toggle between different functions.

Collapsible toggles and accordions can be used to make article content easier for visitors to navigate and read by reducing the amount of scrolling required. This is especially useful for sites that have long articles or that want to maximize the amount of information they can display on their pages.

When used to implement A/B testing or multivariate experiments, toggles bucket your users into different cohorts and at runtime the Toggle Router consistently sends a given user down one of your experiment’s code paths. By tracking the aggregate behavior of these different cohorts you can determine which variants are most effective in improving your product’s performance.

Permission Toggles are typically very short-lived compared to other types of toggles, as they’re used to manage features that are exposed to premium users. These types of toggles are commonly deployed as a part of your monetization strategy and can be changed very frequently, since they’re often managed at the user level.

Managing toggle configuration via static files becomes cumbersome at scale, and requires that the configuration be re-deployed in order to change its state. To address this, many organizations use a central repository of feature flag configuration, either an existing application DB or a service such as Kameleoon, that allows for dynamic in-memory re-configuration during runtime. This reduces deployment overhead, increases the speed at which features can be deployed and connected to contextual data, empowering your team to move faster with confidence.