Swift Charts Accessibility, Fallback, and Resources

Accessibility
- Meaningful Labels
- Custom Audio Graphs
Composite Example
Fallback Strategies
- Version Breakdown
WWDC Sessions
Summary Checklist

Accessibility

Swift Charts provides built-in accessibility support. VoiceOver users get three rotor actions automatically:

Describe Chart — overview of axes and data series
Audio Graph — sonification where pitch represents data values
Chart Detail — interactive mode for exploring individual data points

Meaningful Labels

Always use clear, descriptive strings in .value(_, _) calls. These labels are read by VoiceOver and used in the Audio Graph.

// Good — descriptive labels
LineMark(
    x: .value("Date", entry.date),
    y: .value("Daily Steps", entry.count)
)

// Bad — generic labels
LineMark(
    x: .value("X", entry.date),
    y: .value("Y", entry.count)
)

Custom Audio Graphs

For advanced accessibility, conform your chart view to AXChartDescriptorRepresentable and implement makeChartDescriptor(). Attach it with .accessibilityChartDescriptor(self).

struct StepsChart: View, AXChartDescriptorRepresentable {
    let steps: [DailySteps]

    var body: some View {
        Chart(steps) { day in
            LineMark(x: .value("Date", day.date), y: .value("Steps", day.count))
        }
        .accessibilityChartDescriptor(self)
    }

    func makeChartDescriptor() -> AXChartDescriptor {
        guard let first = steps.first, let last = steps.last else {
            return AXChartDescriptor(title: "Daily Step Count", summary: nil,
                xAxis: AXNumericDataAxisDescriptor(title: "Date", range: 0...1, gridlinePositions: []) { "\($0)" },
                yAxis: AXNumericDataAxisDescriptor(title: "Steps", range: 0...1, gridlinePositions: []) { "\($0)" },
                additionalAxes: [], series: [])
        }
        let xAxis = AXDateDataAxisDescriptor(
            title: "Date", range: first.date...last.date, gridlinePositions: [])
        let yAxis = AXNumericDataAxisDescriptor(
            title: "Steps", range: 0...Double(steps.map(\.count).max() ?? 0),
            gridlinePositions: []) { "\(Int($0)) steps" }
        let series = AXDataSeriesDescriptor(
            name: "Daily Steps", isContinuous: true,
            dataPoints: steps.map { .init(x: $0.date, y: Double($0.count)) })
        return AXChartDescriptor(title: "Daily Step Count", summary: nil,
            xAxis: xAxis, yAxis: yAxis, additionalAxes: [], series: [series])
    }
}

Composite Example

A scrollable bar chart with range selection combining multiple iOS 17+ APIs:

@State private var selectedRange: ClosedRange<Int>?

Chart(weeklyRevenue) { week in
    BarMark(x: .value("Week", week.index), y: .value("Revenue", week.revenue))
        .foregroundStyle(by: .value("Region", week.region))
}
.chartScrollableAxes(.horizontal)
.chartXVisibleDomain(length: 8)
.chartXSelection(range: $selectedRange)
.chartXAxis {
    AxisMarks(values: .stride(by: 1)) {
        AxisGridLine()
        AxisValueLabel { Text("W\($0.as(Int.self) ?? 0)") }
    }
}

Fallback Strategies

Gate advanced APIs with #available and provide a fallback chart without the gated features. Because chart modifiers like .chartXSelection change the return type, you must duplicate the entire Chart — you cannot conditionally apply the modifier:

Version Breakdown

iOS 16+: Chart, custom axes, scales, BarMark, LineMark, AreaMark, PointMark, RectangleMark, RuleMark, ChartProxy, chartOverlay, chartBackground
iOS 17+: SectorMark, chartXSelection, chartYSelection, chartAngleSelection, chartScrollableAxes, visible-domain scrolling APIs, chartGesture
iOS 18+: AreaPlot, BarPlot, LinePlot, PointPlot, RectanglePlot, RulePlot, SectorPlot, function plotting
iOS 26+: Chart3D, SurfacePlot, Z-axis marks, 3D camera and pose APIs

WWDC Sessions

Hello Swift Charts (WWDC 2022) — introduction to the framework
Swift Charts: Raise the bar (WWDC 2022) — marks, composition, customization
Design an effective chart (WWDC 2022) — chart design principles
Design app experiences with charts (WWDC 2022) — integrating charts into app UX
Explore pie charts and interactivity in Swift Charts (WWDC 2023) — SectorMark, selection, scrolling
Swift Charts: Vectorized and function plots (WWDC 2024) — LinePlot, AreaPlot, function plotting
Bring Swift Charts to the third dimension (WWDC 2025) — Chart3D, SurfacePlot, 3D marks

Swift Charts Accessibility, Fallback, and Resources

Swift Charts Accessibility, Fallback, and Resources

Table of Contents

Accessibility

Meaningful Labels

Custom Audio Graphs

Composite Example

Fallback Strategies

Version Breakdown

WWDC Sessions

Summary Checklist