Accessiiblity inspector warnings about Dynamic Type font sizes are unsupported

[pylapp]

Context

With Xcode it is possible to use the developer tool Accessibility Inspector to run accessibility audits for apps.
Users notified us some warnings occur about Dynamic Type: Dynamic Type font size are unsupported.
Detailed message is User will not be able to change the font size of this SwiftUI.AccessibilityNode.
However, the items for which these warnings are sent manages Dynamic Type.

Indeed in the TypographyModifier view modifier, the line height is scaled like (see Swift source file):

    private var scaledLineHeight: CGFloat {
        #if os(macOS)
        adaptiveFontToken.lineHeight
        #else
        UIFontMetrics.default.scaledValue(for: adaptiveFontToken.lineHeight)
        #endif
    }

We reproduced the warning in the design system toolbox (see Swift source file), even for a text with this modifier behind:

// In design toolbox app
Text(namedFont.rawValue.camelCase).displayLarge(theme) // "DisplayLarge" text

calling

// In OUDS View+Tyography.swift
public func displayLarge(_ theme: OUDSTheme) -> some View {
        modifier(TypographyModifier(family: theme.fontFamily, font: theme.fonts.displayLarge))
}

using in the end

// Font composite semantic token defined in theme
@objc open var displayLarge: MultipleFontCompositeSemanticToken { MCT(
                                                                          compact: CT(size: sizeDisplayLargeMobile,
                                                                                      lineHeight: lineHeightDisplayLargeMobile,
                                                                                      weight: weightDisplay,
                                                                                      letterSpacing: letterSpacingDisplayLargeMobile),
                                                                          regular: CT(size: sizeDisplayLargeTablet,
                                                                                      lineHeight: lineHeightDisplayLargeTablet,
                                                                                      weight: weightDisplay,
                                                                                      letterSpacing: letterSpacingDisplayLargeTablet)) }

Suggestion

Maybe, as suggested by reporter, use another API. Instead of UIFontMetrics.default.scaledValue(for:) we should try relativeTo: or scaledFont(for:).

Thanks reporter @karlcosse!

Resources

Accessibility inspector warning

Target text on design system toolbox app

Dynamic rendering

ScreenRecording_07-16-2026.11-55-18_1.MP4

[pylapp]

cc @ludovic35 @pya35

[pylapp]

Another sample

Thanks @karlcosse

Text(text)
       .multilineTextAlignment(.leading)
       .padding(
        .horizontal,
        horizontalSizeClass == .compact ? theme.spaces.scaledMediumMobile : theme.spaces.scaledMediumTablet
       )
       .padding(.bottom, theme.spaces.fixedMedium)
       .headingSmall(theme) // <------ view modifier called here (@pylapp)
       .foregroundColor(theme.colors.contentDefault)
       .frame(alignment: .leading)
       .accessibilityHidden(true)

and inspector warning:

- [Dynamic Type] Dynamic Type font sizes are partially unsupported → StaticText label='Voir tout' @(343,718) 46×14
    t =    40.74s Find the Any (Descendant with identity binding to AX element pid: 15928, elementOrHash.elementID: 5981724096.154)
    t =    40.82s Find the "Mail" StaticText
    t =    40.90s Find the "Mail" StaticText
    t =    40.99s Find the "Mail" StaticText
    t =    41.07s Find the "Mail" StaticText