Apple (xip, downloads):

Xcode 27 includes Swift 6.4 and SDKs for iOS 27, iPadOS 27, tvOS 27, watchOS 27, macOS 27, and visionOS 27. Xcode 27 supports on-device debugging in iOS 17 and later, tvOS 17 and later, watchOS 10 and later, and visionOS. Xcode 27 requires a Mac running macOS Tahoe 26.6 or later.

Peter Witham:

Is this new in Xcode 27? Pretty sure it as and I approve whole heartedly! I really hate setting up Xcode settings more than once.

Christian Beer:

Building with Xcode 27 doesn’t work because of some intransparent XCStrings error… and I even can’t check with Xcode 26 anymore because Apple decided to not let me run it on macOS 27…

Steven Woolgar:

After all these years Apple has finally broken cmd-e in Xcode 27.

Previously:

• iPhone Duo
• Ending the Golden Era for Backward-Compatible Apps
• Xcode 26.6
• Xcode 27’s Device Hub
• Swift 6.4
• Xcode 27 Announced

Update (2026-09-18): Jesse Squires:

Xcode 27 seems to have broken UI appearance vs Editor appearance. They used to be separate settings.

For example, previously, the app could be light mode while the editor theme was dark.

But now, you choose a dark editor theme and the whole app goes to dark mode.

I hate this.

Me, too.

Update (2026-09-24): Christian Beer:

• generate stubs for protocol: uses wrong class names
• fix for missing parameter: inserts it at the wrong position
• generating init with Bindings, State, etc.: mostly wrong

Update (2026-10-01): Steve Troughton-Smith:

AI code completion was such a nothingburger, for all of that investment. I don’t even have it turned on in Xcode anymore. If you’re into code completion, you’re into using Codex and Claude, so why would you ever use it now.

The built-in Xcode stuff has pretty much never worked at all for me. I either get errors or it does nothing.

Craig Hockenberry:

It looks like Xcode 27.1 is needed to test the iPhone Duo resizability - and that hasn’t been uploaded yet.

Jordan Morgan:

Cupertino and Friends™️ dropped six new videos over developing, designing, and crafting great apps for the nascent device:

1. Design for iPhone Duo
2. Prepare your app for iPhone Duo
3. Raise the bar with iPhone Duo
4. Strike a pose with adaptive layouts on iPhone Duo
5. Leverage multiple displays and scenes on iPhone Duo
6. Build a great camera experience for iPhone Duo

Nathan Manceaux-Panot:

In the Duo dev video, they describe how text buttons can’t be moved to the new vertical sidebar, as opposed to icon buttons.

I wonder if that’s one of the reasons Liquid Glass pushed hard for icon buttons, even though these are harder to understand; they make the vertical layout possible at all.

Nico Reese:

Totally confusing to me how the toolbar is ordered completely different between both modes here.

Dennis Oberhoff:

I think the problem with the iPhone Duo for developers is mostly that it does not create any new opportunities in the form of a new market or a new audience.

Previously:

• iPhone Duo
• SwiftUI Toolbars

Update (2026-09-17): See also: Accidental Tech Podcast.

Previously:

• Jumping to 27.2

Update (2026-09-18): Xcode 27.1 Beta (Hacker News) adds support for iPhone Duo, but:

StandBy is unavailable in the iPhone Duo Simulator runtime.

Running and debugging most app extensions is unavailable in the iPhone Duo Simulator runtime.

Update (2026-09-21): Léo Natan:

Apple writing example code in Objective C, in 2026. They are REALLY desperate for developers to support this device.

Natalia Panferova:

On iPhone Duo, navigation controls, toolbar actions, and tabs can move into a shared vertical bar along the edge of the display, leaving more vertical space for content. Apps built with the iOS 27.1 SDK get this adaptation through standard containers such as NavigationStack, NavigationSplitView, and TabView. We continue to declare toolbar actions in their usual placements, and SwiftUI determines how to present them in the current context.

Imthaz Ahamed:

I was going through the iPhone Duo specs and realised the inner screen has a different pixel density to the outer screen. The inner 7.6-inch folding display runs at 1878×2670 and 430 ppi, while the outer 5.4-inch display runs at 1398×2034 and 460 ppi.

Jesper:

The iPhone Duo remains interesting, and is clearly a technical tour-de-force that is the outcome of deep thinking about what a foldable phone can be. But the things that sparkle in my mind when I consider it is just the details. They are very important details that yield a noticeably different product, but they are sprinkles on top of a downward slope in user interface design at Apple that does not care any longer about what users or developers want. All that's important is for this year's device to uproot fundamentals and demand that everyone conform to an arbitrary new intuition.

Update (2026-09-29): Craig Hockenberry:

I don’t remember seeing this mentioned anywhere, but you have to be careful about where you place your safe area constraints.

My first pass moved the constraints on scroll/collection views from the superview leading/trailing to the safe area leading/trailing.

[…]

But if you look at Settings and Safari - our only two examples of “what’s right”, you’ll see the scroll indicators are “outside” the navigation bar and hug the edge of the device bezel.