Device Hub in Xcode 27

To check that your layout adapts to different sizes without running on several simulators, run the app, click Enter resize mode in the canvas toolbar, then drag a handle on the top, bottom or sides, or type dimensions below the simulator. Device Hub snaps to the nearest valid size; click Exit resize mode when done. Apple’s release notes say resize mode isn’t supported for apps linked against the iOS 26 SDK or earlier and can show a black screen, so build with the iOS 27 SDK first. Resizable iPhone apps matter more now, see building for iPhone Duo. Separately, the canvas zoom controls and Physical Size button change only how big the device appears on your Mac.

For a wireless pair, the iPhone or iPad must run iOS or iPadOS 27 or later and be on the same Wi-Fi as your Mac: click Add Device (+), choose Pair Nearby Device…, pick the device type and follow the steps, which may include turning on Developer Mode. Apple Watch needs Developer Mode on both the watch and its iPhone; tvOS and visionOS need IPv6 on the network and a PIN shown on the device. After an OS upgrade you need to pair again. With a cable, connect, tap Trust, and click Pair in Device Hub. Once paired, select the device and click View Screen to control it from your Mac while it stays usable in your hand. Launching Phone or FaceTime on the device stops that session, and quitting them lets you click View Screen again.

devicectl manages simulated and physical devices from Terminal: list devices, install and launch apps, copy files, and read crash logs. Use --json-output in scripts rather than parsing Terminal output, which Apple says can change between releases. Start simulators with xcrun simctl or the Start button in Device Hub. Paired and started devices also mount under ~/Library/Developer/CoreDevice/DeviceFS, shown as Devices in Finder. For coding agents, the Xcode 27 MCP server gained tools to list and switch run destinations and to drive the debugger. For running agents inside an IDE on the Android side, see Claude and Codex in Android Studio.

Apple lists these in the release notes: viewing video from or sending input to a physical Apple Vision Pro isn’t supported (use AirPlay from the headset), Device Hub can’t send a two-finger touch, and during parallel testing simulators may not appear in Device Hub while still running tests. A bug where the CarPlay Simulator couldn’t connect when opened through Device Hub is marked fixed. Xcode 27 itself needs macOS Tahoe 26.6 or later and includes Swift 6.4, covered in what’s new in Swift 6.4.

Testing on every screen size helps your app hold up; being found brings people to it. Censuus ranks apps by the visits they draw, and adding your app is free through the List my app form. Placement comes from traffic and sponsorship: apps climb on the visits they draw, and a sponsor can pay to rise higher. For the App Store side of the 27 SDKs, see the Xcode and SDK upload requirement.