A toggle is a user interface component that allows users to select between two states of a setting or view. Toggles are often used to change system settings or preferences (i.e. state changes), and they are a preferred control type for mobile applications because they take up less screen space than two radio buttons. When designing toggles, it is important to consider a few key best practices: provide direct and clear labels, use standard visual design, and deliver immediate results.
Feature toggles support newer agile development models by enabling your team to release software even while the user’s newly requested features are still in progress. Under more traditional waterfall development models, those features would be written on a separate code branch and then go through a testing and QA process before they could be merged into the trunk codebase and released to users.
Toggles are great for enabling A/B tests and other experiments with your product’s user base. For example, let’s say our e-commerce company is trying to decide which of their product configurator suggestion algorithms provides the best experience for customers. They can create a separate, experimental branch of the product and deploy it to a small cohort of users with an experiment toggle, so they can see which algorithm performs better. After the experiment is complete, they can set the toggle to the winning algorithm and roll it out to the entire user base.
In addition to making it easier for your teams to test new ideas, using feature toggles also helps you keep a clean and consistent codebase. It’s tempting to create a large number of toggles that switch on and off for multiple different conditions, but you should avoid doing this. This can lead to complex and confusing toggle logic, which will be difficult for anyone on your team to debug if it goes wrong down the road.
When you manage a large number of toggles, it’s important to organize them in a central repository so that everyone has access to the same set of changes. It’s also important to have a good communication process so that everyone understands how each toggle works. Creating a detailed documentation of the toggles in your codebase is helpful for maintaining a high level of consistency and understanding.
The word “toggle” comes from the verb to bind, fasten, or connect by passing a rod or pin transversely through an eye or loop in a chain, rope, etc. Toggle is also the name of a device for fastening a toggle rail to a frame. The Oxford English Dictionary notes that the first recorded use of this word was in the mid 18th century.
