On macOS 26, how do you support the Preferred Text Size value as defined in the Accessibility Settings?
Historically, "Dynamic Type" has not been available on macOS. However, the user has some control over text size through the Accessibility Settings.
On macOS 26, a small subset of applications are honouring changes to that value include Finder, Mail, and sidebars in many applications.
Dynamic sizing in table views has been available on macOS for awhile. But Mail.app, in particular, is also adjusting the font sizes used in the message's body pane while the Finder is adjusting font sizes used for Desktop icons.
I can't find an NSNotification that is fired when the user adjusts the Accessibility Text Size slider, nor can I find an API to read the current value.
NSFont.preferredFont(forTextStyle:options:) looks promising but the fonts returned do not appear to take the user's Accessibility setting into account. (Nor do they update dynamically.)
SwiftUI's Text("Apple").font(.body) performs similarly to NSFont in that it does respect the style, but it does not honour dynamic sizing.
NSFontDescriptor has a bunch of interesting methods, but none that seem to apply to Accessibility Text Size.
Given an AppKit label:
let label = NSTextField(labelWithString: "AppKit")
label.font = NSFont.preferredFont(forTextStyle: .body)
Or a SwiftUI label:
Text("SwiftUI").font(.body)
How do I make either of them responsive to the user's Text Size setting under Accessibility?
Note this is on macOS 26 / Xcode 26. I realize there have been some previous forum posts related to this issue but hoping that things might have improved since then.
