What Is a Toggle?

The Toggle is an element that allows you to control the behavior of your application at runtime. This makes it very useful for feature experimentation and as a circuit breaker of sorts for your platform, temporarily disabling non-essential features during high-traffic periods. In addition, it can be used to manage the behavior of your product with users (e.g., by enabling and disabling certain features based on the user’s subscription status).

The best way to create accessible toggles is to use a service like Kameleoon which enables you to dynamically change your feature flag configuration at scale without deploying new code. The alternative is to hard-code your toggle configuration into static files which can be cumbersome and difficult to modify once the feature flag reaches critical mass.

A good practice is to use a clear name for your toggle so that someone reading the code can understand what the toggle does and whether it’s active or inactive. This can be important for preventing accidental inactivation or activation and helps your team maintain an effective logging system. It’s also important to avoid relying solely on color to convey toggle state since this can be confusing for people with low-contrast vision or who associate red with stop signs.

Savvy teams view the Feature Toggles in their codebase as inventory that comes with a carrying cost so they seek to keep the inventory low by adding a task to the team’s backlog for removing toggles once they’re no longer needed and building this process into the tool. Some teams even put expiration dates on their toggles so that they fail tests or even refuse to start a service if they haven’t been updated for over a certain amount of time.