Detecting Xcode Previews
This reference article covers how to use environment values to detect if a process is running in a Xcode preview.

Since it was announced in 2019, SwiftUI developers have been making extensive use of the new canvas. The canvas allows you to get a quick preview of what you're programming and, especially for frontend developers, is a great help to get going quickly.
Xcode statically discovers preview providers (PreviewProvider
) in your project and generates previews for any providers currently open in the source editor. Xcode generates the preview using the current run destination as a hint for which device to display.
However, it is also often useful to know when Xcode is or is not running the code in a preview in order to conditionally choose which data to use to build our app UI. There is no official built-in way to do this. However, we can include in Apple's environment values an additional value that helps us with our goal.
Let's have a look. Become a free member or log in to proceed.