WWDC23 SALE: Save 50% on all my Swift books and bundles! >>

How to detect your iOS app is running on macOS Catalyst

Swift version: 5.6

Paul Hudson    @twostraws   

Although Catalyst does a good job of making UIKit work on macOS, you will quickly realize that some things that worked great on iOS just aren’t great fits for macOS.

So, if you want to detect when your iOS app is running on macOS using Catalyst, you can add an #if targetEnvironment check to provide alternative functionality, like this:

#if targetEnvironment(macCatalyst)
    print("UIKit running on macOS")
    print("Your regular code")

If that file also happens to support other platforms such as watchOS and tvOS, you can add further checks as needed like this:

#if targetEnvironment(macCatalyst)
    print("UIKit running on macOS")
#elseif os(watchOS)
    print("Running on watchOS")
    print("Your regular code")

Detecting Catalyst is particularly useful when removing behavior that, while appropriate on iOS itself, doesn’t look great on macOS. For example, having screens full of information slide onto a UINavigationController looks great on iPhone, OK on iPad, but downright ugly on macOS, so you might want to push view controllers without animation when running on Catalyst.

Save 50% in my WWDC23 sale.

SAVE 50% To celebrate WWDC23, all our books and bundles are half price, so you can take your Swift knowledge further without spending big! Get the Swift Power Pack to build your iOS career faster, get the Swift Platform Pack to builds apps for macOS, watchOS, and beyond, or get the Swift Plus Pack to learn advanced design patterns, testing skills, and more.

Save 50% on all our books and bundles!

Available from iOS 13.0

Similar solutions…

About the Swift Knowledge Base

This is part of the Swift Knowledge Base, a free, searchable collection of solutions for common iOS questions.

Buy Pro Swift Buy Pro SwiftUI Buy Swift Design Patterns Buy Testing Swift Buy Hacking with iOS Buy Swift Coding Challenges Buy Swift on Sundays Volume One Buy Server-Side Swift Buy Advanced iOS Volume One Buy Advanced iOS Volume Two Buy Advanced iOS Volume Three Buy Hacking with watchOS Buy Hacking with tvOS Buy Hacking with macOS Buy Dive Into SpriteKit Buy Swift in Sixty Seconds Buy Objective-C for Swift Developers Buy Beyond Code

Was this page useful? Let us know!

Average rating: 4.7/5

Unknown user

You are not logged in

Log in or create account

Link copied to your pasteboard.