watchos-design-guidelines

name	watchos-design-guidelines
description	Apple Human Interface Guidelines for Apple Watch. Use when building watchOS apps, complications, or workout features. Triggers on tasks involving Watch UI, Digital Crown, glanceable interfaces, or wrist-based interactions.
license	MIT
metadata	{"author":"platform-design-skills","version":"1.0.0"}

watchOS Design Guidelines

Apple Watch is a personal, glanceable device worn on the wrist. Interactions are measured in seconds, not minutes. Every design decision must prioritize speed of comprehension and brevity of interaction.

---

1. Glanceable Design (CRITICAL)

The defining constraint of watchOS. If a user cannot extract the key information within 2 seconds of raising their wrist, the design has failed.

Rules

• W-GL-01: Primary information must be visible without scrolling. The first screen is the only guaranteed screen.
• W-GL-02: Target interaction sessions of 5 seconds or less. Design for raise-glance-lower.
• W-GL-03: Use large, high-contrast text. Minimum effective body text is 16pt (system font). Titles should be 18pt or larger.
• W-GL-04: Limit text to essential content. Truncate or abbreviate aggressively. Use SF Symbols instead of text labels where meaning is unambiguous.
• W-GL-05: Respect wrist-down time. When the wrist lowers, the app enters an inactive state. Do not assume continuous user attention.
• W-GL-06: Prioritize a single piece of information per screen. If showing multiple data points, establish clear visual hierarchy with size, weight, and color.

Screen Dimensions Reference

Device	Screen Width	Screen Height	Corner Radius
41mm (Series 9)	176px	215px	36px
45mm (Series 9)	198px	242px	39px
42mm (Series 10)	180px	220px	37px
46mm (Series 10)	205px	251px	40px
49mm (Ultra 2)	205px	251px	40px

Anti-Patterns

• Walls of text requiring scroll to understand context
• Small, dense data tables
• Requiring multiple taps before showing useful information
• Replicating an iPhone screen layout on Watch

---

2. Digital Crown (HIGH)

The Digital Crown is the primary physical input for scrolling and precise value selection. It provides haptic feedback and should feel purposeful.

Rules

• W-DC-01: Use the Digital Crown as the primary scroll mechanism for vertical content. Do not rely solely on swipe gestures for scrolling.
• W-DC-02: For value pickers (time, quantity, sliders), bind the Crown to precise adjustments with haptic detents at each discrete value.
• W-DC-03: Do not override or conflict with system Crown behaviors. The system uses the Crown for volume control during media playback, scrolling in system UI, and Time Travel in complications.
• W-DC-04: Provide visual feedback synchronized with Crown rotation. The UI must respond frame-by-frame to Crown input with no perceptible lag.
• W-DC-05: Update on each Crown increment. Values, selection, and highlight states should move with each detent. Do not debounce Crown input until the gesture ends.

Correct — Crown binding with haptic detents:

struct VolumePickerView: View {
    @State private var volume: Double = 0.5

    var body: some View {
        VStack {
            Text("\(Int(volume * 100))%")
                .font(.title.bold())
            Image(systemName: "speaker.wave.3")
        }
        .focusable()
        .digitalCrownRotation(
            $volume,
            from: 0.0,
            through: 1.0,
            by: 0.05,
            sensitivity: .medium,
            isContinuous: false,
            isHapticFeedbackEnabled: true
        )
    }
}

Incorrect — ignoring the Crown and forcing touch-only interaction:

struct VolumePickerView: View {
    @State private var volume: Double = 0.5

    var body: some View {
        Slider(value: $volume)
        // No .digitalCrownRotation — Crown input is ignored
        // Users must use touch-only, which is imprecise and frustrating on Watch
    }
}

Anti-Patterns

• Ignoring the Crown and forcing all interaction through touch
• Custom Crown behaviors that conflict with system expectations
• Missing haptic feedback on discrete value changes
• Laggy or batched responses to Crown rotation

---

3. Navigation (HIGH)

Watch navigation must be shallow and predictable. Users should never feel lost or unable to return to a known state.

Rules

• W-NV-01: Use vertical page scrolling as the default content navigation pattern. Pages scroll top-to-bottom with the Digital Crown.
• W-NV-02: Use TabView for top-level sections (max 5 tabs). Swipe horizontally between tabs. Each tab is a distinct functional area.
• W-NV-03: Use NavigationStack for hierarchical drill-down. Limit hierarchy to 2-3 levels maximum. Every pushed view must have a back button (provided automatically by the system).
• W-NV-04: Avoid modal sheets for primary flows. Modals should be reserved for focused, single-purpose tasks (e.g., confirmation, quick input).
• W-NV-05: The app's most important action should be reachable within 1 tap from launch. Do not bury primary functionality behind menus or navigation.

Navigation Pattern Reference

Pattern	Use Case	Gesture
Vertical scroll	Long-form content within a single view	Digital Crown / swipe up-down
TabView (horizontal pages)	Top-level app sections	Swipe left-right
NavigationStack (push/pop)	Hierarchical drill-down	Tap to push, swipe right or back button to pop
Modal sheet	Confirmation, focused input	Presented programmatically, dismiss via button or swipe down

Anti-Patterns

• Deep navigation hierarchies (4+ levels)
• Hamburger menus or hidden navigation drawers
• Tab bars with more than 5 items
• Forcing users to scroll through long lists to find key actions

---

4. Complications (HIGH)

Complications are the most visible surface of a Watch app. They live on the watch face and provide at-a-glance data without launching the app.

Rules

• W-CP-01: Support multiple complication families to maximize watch face compatibility. At minimum support accessoryCircular, accessoryCorner, and accessoryRectangular (WidgetKit, watchOS 9+).
• W-CP-02: Provide both tinted (single-color) and full-color variants. Tinted complications must remain legible when the system applies a single tint color.
• W-CP-03: Update complications via TimelineProvider. Provide future timeline entries when data is predictable (e.g., next calendar event, weather forecast). Keep data fresh -- stale complications erode trust.
• W-CP-04: Complication content must be meaningful without context. A user glancing at their watch face should immediately understand the data (e.g., "72F" not "72").
• W-CP-05: Tapping a complication must launch the app to a relevant context, not just the app's root view.

Correct — WidgetKit TimelineProvider for an accessoryCircular complication:

struct StepCountProvider: TimelineProvider {
    func placeholder(in context: Context) -> StepEntry {
        StepEntry(date: Date(), steps: 5000)
    }

    func getSnapshot(in context: Context, completion: @escaping (StepEntry) -> Void) {
        completion(StepEntry(date: Date(), steps: HealthStore.shared.todaySteps))
    }

    func getTimeline(in context: Context, completion: @escaping (Timeline<StepEntry>) -> Void) {
        let entry = StepEntry(date: Date(), steps: HealthStore.shared.todaySteps)
        // Refresh in 15 minutes
        let nextUpdate = Calendar.current.date(byAdding: .minute, value: 15, to: Date())!
        completion(Timeline(entries: [entry], policy: .after(nextUpdate)))
    }
}

struct StepCountComplicationView: View {
    let entry: StepEntry

    var body: some View {
        Gauge(value: Double(entry.steps), in: 0...10000) {
            Image(systemName: "figure.walk")
        } currentValueLabel: {
            Text("\(entry.steps / 1000)k")
        }
        .gaugeStyle(.accessoryCircular)
    }
}

Complication Family Reference

Use WidgetFamily values:

Family	Shape	Typical Content
accessoryCircular	Small circle	Single value, icon, or gauge
accessoryCorner	Curved, top corners	Gauge with label, or text with icon
accessoryRectangular	Wide rectangle	Multi-line text, chart, or detailed view
accessoryInline	Text row	Short label or value

Anti-Patterns

• Supporting only one complication family
• Stale data that does not update for hours
• Complication tap landing on generic app home instead of relevant content
• Illegible complications in tinted mode (insufficient contrast)

---

5. Always On Display (MEDIUM)

When the user's wrist is down, watchOS enters an Always On state showing a dimmed version of the current app. This must be handled intentionally.

Rules

• W-AO-01: Reduce visual complexity in the Always On state. Remove animations, secondary UI elements, and non-essential detail. Keep only the most critical information visible.
• W-AO-02: Hide sensitive or private data (e.g., message content, health details, financial information) in the dimmed state. Use redacted or placeholder content.
• W-AO-03: Reduce update frequency in Always On. Update the display no more than once per minute. Use TimelineView with a .everyMinute schedule for time-sensitive content.
• W-AO-04: Use the system-provided dimming behaviors. Do not implement custom dimming. The system automatically reduces brightness and can apply a tint. Ensure your content remains legible at reduced brightness.
• W-AO-05: Test both active and Always On states. The transition between states must feel seamless -- layout should not shift or jump when the wrist raises.

Anti-Patterns

• Showing identical UI in active and Always On states (wastes battery, may expose private data)
• Animations or frequent updates in Always On state
• Layout shifts when transitioning between active and dimmed states
• Forgetting to redact sensitive information

---

6. Workouts & Health (MEDIUM)

Workout and health apps have unique requirements: extended sessions, live metrics, and body-awareness features.

Rules

• W-WK-01: Display live workout metrics in large, high-contrast text. Heart rate, duration, distance, and calories should be readable mid-exercise without stopping.
• W-WK-02: Use haptic feedback for milestones (lap completed, goal reached, heart rate zone change). Haptics are essential because users may not be looking at the screen during exercise.
• W-WK-03: Support auto-pause detection for relevant workout types (running, walking). Users expect the workout to pause when they stop moving and resume when they start again.
• W-WK-04: Enable WaterLock during swimming workouts. This disables the touchscreen to prevent water interaction. The Digital Crown is used to eject water and unlock.
• W-WK-05: Show a clear summary screen at workout completion with key metrics. Allow the user to save or discard the workout with a single action.

Anti-Patterns

• Small metric text that requires squinting or stopping to read
• Missing haptic feedback for important workout events
• No auto-pause support for outdoor workouts
• Requiring complex interaction to end or save a workout

---

7. Notifications (MEDIUM)

Watch notifications must be brief and actionable. The user's wrist is raised for only a moment.

Rules

• W-NT-01: Design Short Look notifications with only a title, app icon, and app name. This is what the user sees on initial wrist raise. It must communicate the notification's purpose instantly.
• W-NT-02: Design Long Look notifications with full content and up to 4 action buttons. The user reaches Long Look by continuing to look at the notification. Include the most useful actions inline.
• W-NT-03: Use appropriate haptic notification types. Match the urgency: .notification for standard alerts, .directionUp for positive events, .directionDown for negative events, .success/.failure/.retry for outcomes.
• W-NT-04: Do not over-notify. Excessive notifications cause users to disable them entirely. Batch non-urgent updates. Reserve Watch notifications for time-sensitive or actionable information.

Haptic Type Reference

Haptic	Use Case
.notification	General alerts
.directionUp	Positive event (goal reached, stock up)
.directionDown	Negative event (stock down, weather warning)
.success	Action completed successfully
.failure	Action failed
.retry	Try again prompt
.start	Activity beginning
.stop	Activity ending
.click	Discrete selection (Crown detent, picker)

Anti-Patterns

• Sending every iPhone notification to the Watch
• Notifications without actionable buttons (forcing app launch)
• Using the same haptic type for all notifications regardless of content
• Long notification text that requires extensive scrolling

---

8. Accessibility (CRITICAL)

Apple Watch supports VoiceOver and other assistive technologies. Complications and app UI must be accessible.

Rules

• W-AC-01: Every interactive element must have a meaningful accessibility label. SF Symbol names are not sufficient labels. Use .accessibilityLabel() on image-only buttons.
• W-AC-02: VoiceOver must be able to navigate all app content. Do not hide essential information from the accessibility hierarchy.
• W-AC-03: Provide accessibility values and hints for custom controls (e.g., gauges, progress indicators, custom pickers). Use .accessibilityValue() and .accessibilityHint().
• W-AC-04: Respect Reduce Motion. Disable or substitute decorative animations when enabled. Use @Environment(\.accessibilityReduceMotion).
• W-AC-05: Respond to Bold Text. When the user enables Bold Text, custom text must adapt. SwiftUI dynamic type handles this automatically; custom-drawn text must check @Environment(\.legibilityWeight).
• W-AC-06: Respond to Increase Contrast. When the user enables Increase Contrast, custom colors must provide higher-contrast variants. Use @Environment(\.colorSchemeContrast) to detect the user's preference.

Correct:

Button(action: startWorkout) {
    Image(systemName: "play.fill")
}
.accessibilityLabel("Start workout")

Incorrect:

Button(action: startWorkout) {
    Image(systemName: "play.fill")
}
// VoiceOver reads "play" — not clear what action this performs

Anti-Patterns

• Image-only buttons with no accessibility label
• Custom controls with no accessibility value or hint
• Animations that do not respect Reduce Motion
• Hiding content from the accessibility tree that sighted users can see

---

Evaluation Checklist

Use this checklist when reviewing a watchOS design or implementation.

Glanceability

• Can the user understand the primary content within 2 seconds?
• Is the most important information visible without scrolling?
• Is body text at least 16pt with sufficient contrast?
• Are interactions completable in under 5 seconds?

Digital Crown

• Does the Crown scroll vertical content?
• Do value pickers provide haptic detents?
• Are there no conflicts with system Crown behaviors?

Navigation

• Is the primary action reachable within 1 tap from launch?
• Is the navigation hierarchy 3 levels or fewer?
• Does every pushed view have a back button?
• Are top-level sections organized in a TabView (if applicable)?

Complications

• Are multiple complication families supported?
• Do complications work in both tinted and full-color modes?
• Is complication data updated via TimelineProvider?
• Does tapping a complication open relevant context?

Always On

• Is sensitive data hidden in the dimmed state?
• Is visual complexity reduced when inactive?
• Is the update frequency limited to once per minute or less?
• Is the transition between active and dimmed seamless (no layout shift)?

Workouts

• Are live metrics displayed in large, high-contrast text?
• Are haptics used for milestones?
• Is auto-pause supported for applicable workout types?
• Is the workout summary accessible with a single action?

Notifications

• Is the Short Look meaningful (title + icon)?
• Does the Long Look include inline actions?
• Are haptic types matched to notification urgency?
• Is notification frequency appropriate (not excessive)?

Accessibility

• All interactive elements have meaningful accessibility labels (no raw SF Symbol names)
• Custom controls provide accessibility values and hints via .accessibilityValue() / .accessibilityHint()
• VoiceOver can navigate all app content — no essential content hidden from the accessibility tree
• Animations respect Reduce Motion (@Environment(\.accessibilityReduceMotion))
• Bold Text preference is respected (SwiftUI handles automatically; custom text checks @Environment(\.legibilityWeight))
• Increase Contrast preference is respected (custom colors provide higher-contrast variants)