A toggle switch is a type of user interface control that allows users to select between two opposing states, such as “on” and “off,” using a different appearance for each state. This control is particularly well-suited to applications where the user may need to quickly and reliably make a choice between two alternatives, like switching cameras in a virtual museum exhibit or changing the video resolution in a video chat.
Because toggle switches require a clear visual signifier for each state they must be carefully designed to avoid confusion. In particular, designers should use high-contrast colors and take societal and cultural differences into account when choosing color for the on position (e.g. red for the on position may be counterintuitive to users who associate it with stop signs and stop lights). Toggles should also be clearly labelled with action text that describes what will happen when the toggle is flipped. Finally, to avoid ambiguity in the user’s perception of the toggle’s state, designers should place the label on the same side as the toggle.
Feature toggles are a great way to allow teams to experiment with changes in production without having to deploy them to all users at once. However, the process of managing feature toggle configuration can become complicated once a team reaches a certain size and the number of toggles grows beyond a few dozen. To address this challenge many organizations choose to move their toggle configuration out of static files into some form of centralized store, often in an existing application database. This is often accompanied by the build-out of some sort of admin UI which will provide product managers, testers and system operators with a convenient method for viewing and modifying the Features Flags associated with a toggle.
Toggle switches are ideal for use on mobile devices, where users can only interact with one screen at a time and where it is more difficult to click multiple elements at once. They can be used in forms to replace checkboxes, but should not be placed in long forms where users need to press a Submit button for changes to take effect. In these situations it is often better to replace the toggle with a single checkbox so that the user can be assured of immediate results.
In addition to the standard toggle style, many platforms support small toggles which are more compact in size and display a checkmark tick for the on position rather than the words On and Off. Small toggles can be useful in condensed spaces and within inline content such as data table rows.
When it comes to testing, it is important for a team to test the toggle configuration which will be live in production, as well as all fallback toggles which will be exposed to premium users. Additionally, it is a good practice for teams to perform some tests with all toggles flipped On so that any future behavior enabled by a feature flag can be tested in isolation.
