ios-design-guidelines

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330204 months ago

Apple Human Interface Guidelines for iPhone. Use when building, reviewing, or refactoring SwiftUI/UIKit interfaces for iOS. Triggers on tasks involving iPhone UI, iOS components, accessibility, Dynamic Type, Dark Mode, or HIG compliance.

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iOS Design Guidelines for iPhone

Comprehensive rules derived from Apple's Human Interface Guidelines. Apply these when building, reviewing, or refactoring any iPhone app interface.

1. Layout & Safe Areas

Impact: CRITICAL

Rule 1.1: Minimum 44pt Touch Targets

All interactive elements must have a minimum tap target of 44x44 points. This includes buttons, links, toggles, and custom controls.

Correct:

Button("Save") { save() }
    .frame(minWidth: 44, minHeight: 44)

Incorrect:

// 20pt icon with no padding — too small to tap reliably
Button(action: save) {
    Image(systemName: "checkmark")
        .font(.system(size: 20))
}
// Missing .frame(minWidth: 44, minHeight: 44)

Rule 1.2: Respect Safe Areas

Never place interactive or essential content under the status bar, Dynamic Island, or home indicator. Use SwiftUI's automatic safe area handling or UIKit's safeAreaLayoutGuide.

Correct:

struct ContentView: View {
    var body: some View {
        VStack {
            Text("Content")
        }
        // SwiftUI respects safe areas by default
    }
}

Incorrect:

struct ContentView: View {
    var body: some View {
        VStack {
            Text("Content")
        }
        .ignoresSafeArea() // Content will be clipped under notch/Dynamic Island
    }
}

Use .ignoresSafeArea() only for background fills, images, or decorative elements — never for text or interactive controls.

Rule 1.3: Primary Actions in the Thumb Zone

Place primary actions at the bottom of the screen where the user's thumb naturally rests. Secondary actions and navigation belong at the top.

Correct:

VStack {
    ScrollView { /* content */ }
    Button("Continue") { next() }
        .buttonStyle(.borderedProminent)
        .padding()
}

Incorrect:

VStack {
    Button("Continue") { next() } // Top of screen — hard to reach one-handed
        .buttonStyle(.borderedProminent)
        .padding()
    ScrollView { /* content */ }
}

Rule 1.4: Support All iPhone Screen Sizes

Design for iPhone SE (375pt wide) through iPhone Pro Max (430pt wide). Use flexible layouts, avoid hardcoded widths.

Correct:

HStack(spacing: 12) {
    ForEach(items) { item in
        CardView(item: item)
            .frame(maxWidth: .infinity) // Adapts to screen width
    }
}

Incorrect:

HStack(spacing: 12) {
    ForEach(items) { item in
        CardView(item: item)
            .frame(width: 180) // Breaks on SE, wastes space on Pro Max
    }
}

Rule 1.5: 8pt Grid Alignment

Align spacing, padding, and element sizes to multiples of 8 points (8, 16, 24, 32, 40, 48). Use 4pt for fine adjustments.

Rule 1.6: Landscape Support

Support landscape orientation unless the app is task-specific (e.g., camera). Use ViewThatFits or GeometryReader for adaptive layouts.

2. Navigation

Impact: CRITICAL

Rule 2.1: Tab Bar for Top-Level Sections

Use a tab bar at the bottom of the screen for 3 to 5 top-level sections. Each tab should represent a distinct category of content or functionality.

Correct:

TabView {
    HomeView()
        .tabItem {
            Label("Home", systemImage: "house")
        }
    SearchView()
        .tabItem {
            Label("Search", systemImage: "magnifyingglass")
        }
    ProfileView()
        .tabItem {
            Label("Profile", systemImage: "person")
        }
}

Incorrect:

// Hamburger menu hidden behind three lines — discoverability is near zero
NavigationView {
    Button(action: { showMenu.toggle() }) {
        Image(systemName: "line.horizontal.3")
    }
}

Rule 2.2: Never Use Hamburger Menus

Hamburger (drawer) menus hide navigation, reduce discoverability, and violate iOS conventions. Use a tab bar instead. If you have more than 5 sections, consolidate or use a "More" tab.

Rule 2.3: Large Titles in Primary Views

Use .navigationBarTitleDisplayMode(.large) for top-level views. Titles transition to inline (.inline) when the user scrolls.

Correct:

NavigationStack {
    List(items) { item in
        ItemRow(item: item)
    }
    .navigationTitle("Messages")
    .navigationBarTitleDisplayMode(.large)
}

Rule 2.4: Never Override Back Swipe

The swipe-from-left-edge gesture for back navigation is a system-level expectation. Never attach custom gesture recognizers that interfere with it.

Incorrect:

.gesture(
    DragGesture()
        .onChanged { /* custom drawer */ } // Conflicts with system back swipe
)

Rule 2.5: Use NavigationStack for Hierarchical Content

Use NavigationStack (not the deprecated NavigationView) for drill-down content. Use NavigationPath for programmatic navigation.

Correct:

NavigationStack(path: $path) {
    List(items) { item in
        NavigationLink(value: item) {
            ItemRow(item: item)
        }
    }
    .navigationDestination(for: Item.self) { item in
        ItemDetail(item: item)
    }
}

Rule 2.6: Preserve State Across Navigation

When users navigate back and then forward, or switch tabs, restore the previous scroll position and input state. Use @SceneStorage or @State to persist view state.

Rule 2.7: Prefer Recognition Over Recall

Keep current location, recent choices, and available destinations visible. Restore tab, scroll, filter, and selection state so users continue from recognition instead of reconstructing context from memory.

3. Typography & Dynamic Type

Impact: HIGH

Rule 3.1: Use Built-in Text Styles

Always use semantic text styles rather than hardcoded sizes. These scale automatically with Dynamic Type.

Correct:

VStack(alignment: .leading, spacing: 4) {
    Text("Section Title")
        .font(.headline)
    Text("Body content that explains the section.")
        .font(.body)
    Text("Last updated 2 hours ago")
        .font(.caption)
        .foregroundStyle(.secondary)
}

Incorrect:

VStack(alignment: .leading, spacing: 4) {
    Text("Section Title")
        .font(.system(size: 17, weight: .semibold)) // Won't scale with Dynamic Type
    Text("Body content")
        .font(.system(size: 15)) // Won't scale with Dynamic Type
}

Rule 3.2: Support Dynamic Type Including Accessibility Sizes

Dynamic Type can scale text up to approximately 200% at the largest accessibility sizes. Layouts must reflow — never truncate or clip essential text.

Correct:

HStack {
    Image(systemName: "star")
    Text("Favorites")
        .font(.body)
}
// At accessibility sizes, consider using ViewThatFits or
// AnyLayout to switch from HStack to VStack

Use @Environment(\.dynamicTypeSize) to detect size category and adapt layouts:

@Environment(\.dynamicTypeSize) var dynamicTypeSize

var body: some View {
    if dynamicTypeSize.isAccessibilitySize {
        VStack { content }
    } else {
        HStack { content }
    }
}

Rule 3.3: Custom Fonts Must Scale with Dynamic Type

If you use a custom typeface, scale it so it responds to Dynamic Type. The API differs by framework.

Correct (SwiftUI):

extension Font {
    static func scaledCustom(size: CGFloat, relativeTo textStyle: Font.TextStyle) -> Font {
        .custom("CustomFont-Regular", size: size, relativeTo: textStyle)
    }
}

// Usage
Text("Hello")
    .font(.scaledCustom(size: 17, relativeTo: .body))

Correct (UIKit):

let metrics = UIFontMetrics(forTextStyle: .body)
let customFont = UIFont(name: "CustomFont-Regular", size: 17)!
label.font = metrics.scaledFont(for: customFont)
label.adjustsFontForContentSizeCategory = true

Rule 3.4: SF Pro as System Font

Use the system font (SF Pro) unless brand requirements dictate otherwise. SF Pro is optimized for legibility on Apple displays.

Rule 3.5: Minimum 11pt Text

Never display text smaller than 11pt. Prefer 17pt for body text. Use the caption2 style (11pt) as the absolute minimum.

Rule 3.6: Hierarchy Through Weight and Size

Establish visual hierarchy through font weight and size. Do not rely solely on color to differentiate text levels.

4. Color & Dark Mode

Impact: HIGH

Rule 4.1: Use Semantic System Colors

Use system-provided semantic colors that automatically adapt to light and dark modes.

Correct:

Text("Primary text")
    .foregroundStyle(.primary) // Adapts to light/dark

Text("Secondary info")
    .foregroundStyle(.secondary)

VStack { }
    .background(Color(.systemBackground)) // White in light, black in dark

Incorrect:

Text("Primary text")
    .foregroundColor(.black) // Invisible on dark backgrounds

VStack { }
    .background(.white) // Blinding in Dark Mode

Rule 4.2: Provide Light and Dark Variants for Custom Colors

Define custom colors in the asset catalog with both Any Appearance and Dark Appearance variants.

// In Assets.xcassets, define "BrandBlue" with:
// Any Appearance: #0066CC
// Dark Appearance: #4DA3FF

Text("Brand text")
    .foregroundStyle(Color("BrandBlue")) // Automatically switches

Rule 4.3: Never Rely on Color Alone

Always pair color with text, icons, or shapes to convey meaning. Approximately 8% of men have some form of color vision deficiency.

Correct:

HStack {
    Image(systemName: "exclamationmark.triangle.fill")
        .foregroundStyle(.red)
    Text("Error: Invalid email address")
        .foregroundStyle(.red)
}

Incorrect:

// Only color indicates the error — invisible to colorblind users
TextField("Email", text: $email)
    .border(isValid ? .green : .red)

Rule 4.4: 4.5:1 Contrast Ratio Minimum

All text must meet WCAG AA contrast ratios: 4.5:1 for normal text, 3:1 for large text (18pt+ or 14pt+ bold).

Rule 4.5: Support Display P3 Wide Gamut

Use Display P3 color space for vibrant, accurate colors on modern iPhones. Define colors in the asset catalog with the Display P3 gamut.

Rule 4.6: Background Hierarchy

Use the three-level background hierarchy for depth:

systemBackground — primary surface
secondarySystemBackground — grouped content, cards
tertiarySystemBackground — elements within grouped content

Rule 4.7: One Accent Color for Interactive Elements

Choose a single tint/accent color for all interactive elements (buttons, links, toggles). This creates a consistent, learnable visual language.

@main
struct MyApp: App {
    var body: some Scene {
        WindowGroup {
            ContentView()
                .tint(.indigo) // All interactive elements use indigo
        }
    }
}

5. Accessibility

Impact: CRITICAL

Rule 5.1: VoiceOver Labels on All Interactive Elements

Every button, control, and interactive element must have a meaningful accessibility label.

Correct:

Button(action: addToCart) {
    Image(systemName: "cart.badge.plus")
}
.accessibilityLabel("Add to cart")

Incorrect:

Button(action: addToCart) {
    Image(systemName: "cart.badge.plus")
}
// VoiceOver reads "cart.badge.plus" — meaningless to users

Rule 5.2: Logical VoiceOver Navigation Order

Ensure VoiceOver reads elements in a logical order. Use .accessibilitySortPriority() to adjust when the visual layout doesn't match the reading order.

VStack {
    Text("Price: $29.99")
        .accessibilitySortPriority(1) // Read second (lower number = lower priority)
    Text("Product Name")
        .accessibilitySortPriority(2) // Read first (higher number = higher priority)
}

Rule 5.3: Support Bold Text

When the user enables Bold Text in Settings, custom-rendered text must adapt. SwiftUI text styles handle this automatically. For SwiftUI custom rendering, use @Environment(\.legibilityWeight) to apply heavier weights. UIKit code must check UIAccessibility.isBoldTextEnabled and re-query on UIAccessibility.boldTextStatusDidChangeNotification.

Correct:

// SwiftUI — standard text styles adapt automatically
Text("Section Header")
    .font(.headline)

// SwiftUI — custom rendering respects legibilityWeight
@Environment(\.legibilityWeight) var legibilityWeight

var body: some View {
    Text("Custom Label")
        .fontWeight(legibilityWeight == .bold ? .bold : .regular)
}

Incorrect:

// Hardcoded weight ignores Bold Text preference
label.font = UIFont.systemFont(ofSize: 17, weight: .regular)
// Missing: re-query font when UIAccessibility.boldTextStatusDidChangeNotification fires

Rule 5.4: Support Reduce Motion

Disable decorative animations and parallax when Reduce Motion is enabled. Use @Environment(\.accessibilityReduceMotion).

Correct:

@Environment(\.accessibilityReduceMotion) var reduceMotion

var body: some View {
    CardView()
        .animation(reduceMotion ? nil : .spring(), value: isExpanded)
}

Rule 5.5: Support Increase Contrast

When the user enables Increase Contrast, ensure custom colors have higher-contrast variants. Use @Environment(\.colorSchemeContrast) to detect.

Rule 5.6: Don't Convey Info Only by Color, Shape, or Position

Information must be available through multiple channels. Pair visual indicators with text or accessibility descriptions.

Rule 5.7: Alternative Interactions for All Gestures

Every custom gesture must have an equivalent tap-based or menu-based alternative for users who cannot perform complex gestures.

Rule 5.8: Support Switch Control and Full Keyboard Access

Ensure all interactions work with Switch Control (external switches) and Full Keyboard Access (Bluetooth keyboards). Test navigation order and focus behavior.

6. Gestures & Input

Impact: HIGH

Rule 6.1: Use Standard Gestures

Use the standard iOS gesture vocabulary: tap, long press, swipe, pinch, rotate. Users already understand these.

Gesture	Standard Use
Tap	Primary action, selection
Long press	Context menu, preview
Swipe horizontal	Delete, archive, navigate back
Swipe vertical	Scroll, dismiss sheet
Pinch	Zoom in/out
Two-finger rotate	Rotate content

Rule 6.2: Never Override System Gestures

These gestures are reserved by the system and must not be intercepted:

Swipe from left edge (back navigation)
Swipe down from top-left (Notification Center)
Swipe down from top-right (Control Center)
Swipe up from bottom (home / app switcher)

Rule 6.3: Custom Gestures Must Be Discoverable

If you add a custom gesture, provide visual hints (e.g., a grabber handle) and ensure the action is also available through a visible button or menu item.

Rule 6.4: Support All Input Methods

Design for touch first, but also support:

Hardware keyboards (iPad keyboard accessories, Bluetooth keyboards)
Assistive devices (Switch Control, head tracking)
Pointer input (assistive touch)

7. Components

Impact: HIGH

Rule 7.1: Button Styles

Use the built-in button styles appropriately:

.borderedProminent — primary call-to-action
.bordered — secondary actions
.borderless — tertiary or inline actions
.destructive role — red tint for delete/remove

Correct:

VStack(spacing: 16) {
    Button("Purchase") { buy() }
        .buttonStyle(.borderedProminent)

    Button("Add to Wishlist") { wishlist() }
        .buttonStyle(.bordered)

    Button("Delete", role: .destructive) { delete() }
}

Rule 7.2: Alerts — Critical Info Only

Use alerts sparingly for critical information that requires a decision. Prefer 2 buttons; maximum 3. The destructive option should use .destructive role.

Correct:

.alert("Delete Photo?", isPresented: $showAlert) {
    Button("Delete", role: .destructive) { deletePhoto() }
    Button("Cancel", role: .cancel) { }
} message: {
    Text("This photo will be permanently removed.")
}

Incorrect:

// Alert for non-critical info — should be a banner or toast
.alert("Tip", isPresented: $showTip) {
    Button("OK") { }
} message: {
    Text("Swipe left to delete items.")
}

Rule 7.3: Sheets for Scoped Tasks

Present sheets for self-contained tasks. Always provide a way to dismiss (close button or swipe down). Use .presentationDetents() for half-height sheets.

.sheet(isPresented: $showCompose) {
    NavigationStack {
        ComposeView()
            .navigationTitle("New Message")
            .toolbar {
                ToolbarItem(placement: .cancellationAction) {
                    Button("Cancel") { showCompose = false }
                }
                ToolbarItem(placement: .confirmationAction) {
                    Button("Send") { send() }
                }
            }
    }
    .presentationDetents([.medium, .large])
}

Rule 7.4: Lists — Inset Grouped Default

Use the .insetGrouped list style as the default. Support swipe actions for common operations. Minimum row height is 44pt.

Correct:

List {
    Section("Recent") {
        ForEach(recentItems) { item in
            ItemRow(item: item)
                .swipeActions(edge: .trailing) {
                    Button(role: .destructive) { delete(item) } label: {
                        Label("Delete", systemImage: "trash")
                    }
                    Button { archive(item) } label: {
                        Label("Archive", systemImage: "archivebox")
                    }
                    .tint(.blue)
                }
        }
    }
}
.listStyle(.insetGrouped)

Rule 7.5: Tab Bar Behavior

Use SF Symbols for tab icons — filled variant for the selected tab, outline for unselected
Never hide the tab bar when navigating deeper within a tab
Badge important counts with .badge()

TabView {
    MessagesView()
        .tabItem {
            Label("Messages", systemImage: "message")
        }
        .badge(unreadCount)
}

Rule 7.6: Search

Place search using .searchable(). Provide search suggestions and support recent searches.

NavigationStack {
    List(filteredItems) { item in
        ItemRow(item: item)
    }
    .searchable(text: $searchText, prompt: "Search items")
    .searchSuggestions {
        ForEach(suggestions) { suggestion in
            Text(suggestion.title)
                .searchCompletion(suggestion.title)
        }
    }
}

Rule 7.7: Context Menus

Use context menus (long press) for secondary actions. Never use a context menu as the only way to access an action.

PhotoView(photo: photo)
    .contextMenu {
        Button { share(photo) } label: {
            Label("Share", systemImage: "square.and.arrow.up")
        }
        Button { favorite(photo) } label: {
            Label("Favorite", systemImage: "heart")
        }
        Button(role: .destructive) { delete(photo) } label: {
            Label("Delete", systemImage: "trash")
        }
    }

Rule 7.8: Progress Indicators

Determinate (ProgressView(value:total:)) for operations with known duration
Indeterminate (ProgressView()) for unknown duration
Never block the entire screen with a spinner

Rule 7.9: SF Symbols — Rendering Modes

Use the appropriate rendering mode for each symbol. Monochrome is the default; hierarchical, palette, and multicolor provide richer expression where appropriate. Always prefer the symbol rendering mode that best communicates meaning — do not default to monochrome when multicolor conveys critical state.

Correct:

// Hierarchical: single color with automatic opacity layers
Image(systemName: "person.crop.circle.fill")
    .symbolRenderingMode(.hierarchical)
    .foregroundStyle(.blue)

// Multicolor: system-defined color per layer (e.g., battery, weather)
Image(systemName: "battery.100percent.bolt")
    .symbolRenderingMode(.multicolor)

// Palette: explicit per-layer colors
Image(systemName: "folder.badge.plus")
    .symbolRenderingMode(.palette)
    .foregroundStyle(.white, .blue)

Incorrect:

// Monochrome on a symbol that has meaningful multicolor layers
Image(systemName: "battery.100percent.bolt")
    .foregroundColor(.gray) // loses the contextual color meaning

Rule 7.10: SF Symbols — Weight and Scale

Match the symbol weight to adjacent text weight. Use scale variants (.small, .medium, .large) rather than resizing. The symbol weight should never appear heavier than adjacent text.

Correct:

Label("Download", systemImage: "arrow.down.circle.fill")
    .font(.body.weight(.semibold))
    // Symbol inherits .semibold weight automatically via Label

Incorrect:

HStack {
    Image(systemName: "arrow.down.circle.fill")
        .font(.system(size: 32)) // explicit size ignores type scale
    Text("Download")
        .font(.body)
}

Rule 7.11: SF Symbols — Animations (iOS 17+)

Use symbolEffect for symbol state transitions. Prefer discrete effects (.bounce, .pulse) for actions and indefinite effects (.variableColor) for ongoing state. Do not use manual cross-fade between symbol names when contentTransition(.symbolEffect) is available.

Correct:

Image(systemName: isLoading ? "arrow.2.circlepath" : "checkmark.circle")
    .contentTransition(.symbolEffect(.replace))
    .symbolEffect(.pulse, isActive: isLoading)

Incorrect:

// Manual opacity cross-fade between symbol names
if isLoading {
    Image(systemName: "arrow.2.circlepath")
} else {
    Image(systemName: "checkmark.circle")
}

8. Patterns

Impact: MEDIUM

Rule 8.1: Onboarding — Max 3 Pages, Skippable

Keep onboarding to 3 or fewer pages. Always provide a skip option. Defer sign-in until the user needs authenticated features.

TabView {
    OnboardingPage(
        image: "wand.and.stars",
        title: "Smart Suggestions",
        subtitle: "Get personalized recommendations based on your preferences."
    )
    OnboardingPage(
        image: "bell.badge",
        title: "Stay Updated",
        subtitle: "Receive notifications for things that matter to you."
    )
    OnboardingPage(
        image: "checkmark.shield",
        title: "Private & Secure",
        subtitle: "Your data stays on your device."
    )
}
.tabViewStyle(.page)
.overlay(alignment: .topTrailing) {
    Button("Skip") { completeOnboarding() }
        .padding()
}

Rule 8.2: Loading — Skeleton Views, No Blocking Spinners

Use skeleton/placeholder views that match the layout of the content being loaded. Never show a full-screen blocking spinner.

Correct:

if isLoading {
    ForEach(0..<5) { _ in
        SkeletonRow() // Placeholder matching final row layout
            .redacted(reason: .placeholder)
    }
} else {
    ForEach(items) { item in
        ItemRow(item: item)
    }
}

Incorrect:

if isLoading {
    ProgressView("Loading...") // Blocks the entire view
} else {
    List(items) { item in ItemRow(item: item) }
}

Rule 8.3: Launch Screen — Match First Screen

The launch storyboard must visually match the initial screen of the app. No splash logos, no branding screens. This creates the perception of instant launch.

Rule 8.4: Modality — Use Sparingly

Present modal views only when the user must complete or abandon a focused task. Always provide a clear dismiss action. Never stack modals on top of modals.

Rule 8.5: Notifications — High Value Only

Only send notifications for content the user genuinely cares about. Support actionable notifications. Categorize notifications so users can control them granularly.

Rule 8.6: Settings Placement

Frequent settings: In-app settings screen accessible from a profile or gear icon
Privacy/permission settings: Defer to the system Settings app via URL scheme
Never duplicate system-level controls in-app

Rule 8.7: Feedback — Visual + Haptic

Provide immediate feedback for every user action:

Visual state change (button highlight, animation)
Haptic feedback for significant actions using UIImpactFeedbackGenerator, UINotificationFeedbackGenerator, or UISelectionFeedbackGenerator

Button("Complete") {
    let generator = UINotificationFeedbackGenerator()
    generator.notificationOccurred(.success)
    completeTask()
}

Rule 8.8: Show Waiting States Immediately

If an action cannot complete immediately, acknowledge the tap at once, then show inline progress, skeletons, or partial results. Never leave the interface visually unchanged while work continues.

9. Privacy & Permissions

Impact: HIGH

Rule 9.1: Request Permissions in Context

Request a permission at the moment the user takes an action that needs it — never at app launch.

Correct:

Button("Take Photo") {
    // Request camera permission only when the user taps this button
    AVCaptureDevice.requestAccess(for: .video) { granted in
        if granted { showCamera = true }
    }
}

Incorrect:

// In AppDelegate.didFinishLaunching — too early, no context
func application(_ application: UIApplication, didFinishLaunchingWithOptions ...) {
    AVCaptureDevice.requestAccess(for: .video) { _ in }
    CLLocationManager().requestWhenInUseAuthorization()
    UNUserNotificationCenter.current().requestAuthorization(options: [.alert]) { _, _ in }
}

Rule 9.2: Explain Before System Prompt

Show a custom explanation screen before triggering the system permission dialog. The system dialog only appears once — if the user denies, the app must direct them to Settings.

struct LocationExplanation: View {
    var body: some View {
        VStack(spacing: 16) {
            Image(systemName: "location.fill")
                .font(.largeTitle)
            Text("Find Nearby Stores")
                .font(.headline)
            Text("We use your location to show stores within walking distance. Your location is never shared or stored.")
                .font(.body)
                .multilineTextAlignment(.center)
            Button("Enable Location") {
                locationManager.requestWhenInUseAuthorization()
            }
            .buttonStyle(.borderedProminent)
            Button("Not Now") { dismiss() }
                .foregroundStyle(.secondary)
        }
        .padding()
    }
}

Rule 9.3: Support Sign in with Apple

If the app offers any third-party sign-in (Google, Facebook), it must also offer Sign in with Apple. Present it as the first option.

Rule 9.4: Don't Require Accounts Unless Necessary

Let users explore the app before requiring sign-in. Gate only features that genuinely need authentication (purchases, sync, social features).

Rule 9.5: App Tracking Transparency

If you track users across apps or websites, display the ATT prompt. Respect denial — do not degrade the experience for users who opt out.

Rule 9.6: Location Button for One-Time Access

Use LocationButton for actions that need location once without requesting ongoing permission.

import CoreLocationUI

LocationButton(.currentLocation) {
    fetchNearbyStores()
}
.labelStyle(.titleAndIcon)

10. System Integration

Impact: MEDIUM

Rule 10.1: Widgets for Glanceable Data

Provide widgets using WidgetKit for information users check frequently. Show the most useful snapshot. Since iOS 17, widgets support interactive controls: use Button and Toggle backed by App Intents for actions users perform directly from the widget without opening the app.

// iOS 17+ interactive widget with a Button
struct TimerWidgetView: View {
    let entry: TimerEntry

    var body: some View {
        VStack {
            Text(entry.remaining, style: .timer)
                .font(.title2.bold())
            Button(intent: ToggleTimerIntent()) {
                Label(entry.isRunning ? "Pause" : "Start",
                      systemImage: entry.isRunning ? "pause.fill" : "play.fill")
            }
            .buttonStyle(.borderedProminent)
        }
    }
}

Rule 10.2: App Shortcuts for Key Actions

Define App Shortcuts so users can trigger key actions from Siri, Spotlight, and the Shortcuts app.

struct MyAppShortcuts: AppShortcutsProvider {
    static var appShortcuts: [AppShortcut] {
        AppShortcut(
            intent: StartWorkoutIntent(),
            phrases: ["Start a workout in \(.applicationName)"],
            shortTitle: "Start Workout",
            systemImageName: "figure.run"
        )
    }
}

Rule 10.3: Spotlight Indexing

Index app content with CSSearchableItem so users can find it from Spotlight search.

Rule 10.4: Share Sheet Integration

Support the system share sheet for content that users might want to send elsewhere. Implement UIActivityItemSource or use ShareLink in SwiftUI.

ShareLink(item: article.url) {
    Label("Share", systemImage: "square.and.arrow.up")
}

Rule 10.5: Live Activities

Use Live Activities and the Dynamic Island for real-time, time-bound events (delivery tracking, sports scores, workouts).

Rule 10.6: Handle Interruptions Gracefully

Save state and pause gracefully when interrupted by:

Phone calls
Siri invocations
Notifications
App switcher
FaceTime SharePlay

Use scenePhase to detect transitions:

@Environment(\.scenePhase) var scenePhase

.onChange(of: scenePhase) { _, newPhase in
    switch newPhase {
    case .active: resumeActivity()
    case .inactive: pauseActivity()
    case .background: saveState()
    @unknown default: break
    }
}

Quick Reference

Need	Component	Notes
Top-level sections (3-5)	`TabView` with `.tabItem`	Bottom tab bar, SF Symbols
Hierarchical drill-down	`NavigationStack`	Large title on root, inline on children
Self-contained task	`.sheet`	Swipe to dismiss, cancel/done buttons
Critical decision	`.alert`	2 buttons preferred, max 3
Secondary actions	`.contextMenu`

Evaluation Checklist

Use this checklist to audit an iPhone app for HIG compliance:

Layout & Safe Areas

All touch targets are at least 44x44pt
No content is clipped under status bar, Dynamic Island, or home indicator
Primary actions are in the bottom half of the screen (thumb zone)
Layout adapts from iPhone SE to Pro Max without breaking
Spacing aligns to the 8pt grid

Navigation

Tab bar is used for 3-5 top-level sections
No hamburger/drawer menus
Primary views use large titles
Swipe-from-left-edge back navigation works throughout
State is preserved when switching tabs

Typography

All text uses built-in text styles or custom fonts scaled with Dynamic Type (Font.custom(_:size:relativeTo:) in SwiftUI or UIFontMetrics in UIKit)
Dynamic Type is supported up to accessibility sizes
Layouts reflow at large text sizes (no truncation of essential text)
Minimum text size is 11pt

Color & Dark Mode

App uses semantic system colors or provides light/dark asset variants
Dark Mode looks intentional (not just inverted)
No information conveyed by color alone
Text contrast meets 4.5:1 (normal) or 3:1 (large)
Single accent color for interactive elements

Accessibility

VoiceOver reads all screens logically with meaningful labels
Bold Text preference is respected
Reduce Motion disables decorative animations
Increase Contrast variant exists for custom colors
All gestures have alternative access paths

Components

Alerts are used only for critical decisions
Sheets have a dismiss path (button and/or swipe)
List rows are at least 44pt tall
Tab bar is never hidden during navigation
Destructive buttons use the .destructive role

Privacy

Permissions are requested in context, not at launch
Custom explanation shown before each system permission dialog
Sign in with Apple offered alongside other providers
App is usable without an account for basic features
ATT prompt is shown if tracking, and denial is respected

System Integration

Widgets show glanceable, up-to-date information
App content is indexed for Spotlight
Share Sheet is available for shareable content
App handles interruptions (calls, background, Siri) gracefully

Anti-Patterns

These are common mistakes that violate the iOS Human Interface Guidelines. Never do these:

Hamburger menus — Use a tab bar. Hamburger menus hide navigation and reduce feature discoverability by up to 50%.
Custom back buttons that break swipe-back — If you replace the back button, ensure the swipe-from-left-edge gesture still works via NavigationStack.
Full-screen blocking spinners — Use skeleton views or inline progress indicators. Blocking spinners make the app feel frozen.
Splash screens with logos — The launch screen must mirror the first screen of the app. Branding delays feel artificial.
Requesting all permissions at launch — Asking for camera, location, notifications, and contacts on first launch guarantees most will be denied.
Hardcoded font sizes — Use text styles. Hardcoded sizes ignore Dynamic Type and accessibility preferences, breaking the app for millions of users.
Using only color to indicate state — Red/green for valid/invalid excludes colorblind users. Always pair with icons or text.
Alerts for non-critical information — Alerts interrupt flow and require dismissal. Use banners, toasts, or inline messages for tips and non-critical information.
Hiding the tab bar on push — Tab bars should remain visible throughout navigation within a tab. Hiding them disorients users.
Ignoring safe areas — Using .ignoresSafeArea() on content views causes text and buttons to disappear under the notch, Dynamic Island, or home indicator.

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iOS Design Guidelines for iPhone

Comprehensive rules derived from Apple's Human Interface Guidelines. Apply these when building, reviewing, or refactoring any iPhone app interface.

1. Layout & Safe Areas

Impact: CRITICAL

Rule 1.1: Minimum 44pt Touch Targets

All interactive elements must have a minimum tap target of 44x44 points. This includes buttons, links, toggles, and custom controls.

Correct:

Button("Save") { save() }
    .frame(minWidth: 44, minHeight: 44)

Incorrect:

// 20pt icon with no padding — too small to tap reliably
Button(action: save) {
    Image(systemName: "checkmark")
        .font(.system(size: 20))
}
// Missing .frame(minWidth: 44, minHeight: 44)

Rule 1.2: Respect Safe Areas

Never place interactive or essential content under the status bar, Dynamic Island, or home indicator. Use SwiftUI's automatic safe area handling or UIKit's safeAreaLayoutGuide.

Correct:

struct ContentView: View {
    var body: some View {
        VStack {
            Text("Content")
        }
        // SwiftUI respects safe areas by default
    }
}

Incorrect:

struct ContentView: View {
    var body: some View {
        VStack {
            Text("Content")
        }
        .ignoresSafeArea() // Content will be clipped under notch/Dynamic Island
    }
}

Use .ignoresSafeArea() only for background fills, images, or decorative elements — never for text or interactive controls.

Rule 1.3: Primary Actions in the Thumb Zone

Place primary actions at the bottom of the screen where the user's thumb naturally rests. Secondary actions and navigation belong at the top.

Correct:

VStack {
    ScrollView { /* content */ }
    Button("Continue") { next() }
        .buttonStyle(.borderedProminent)
        .padding()
}

Incorrect:

VStack {
    Button("Continue") { next() } // Top of screen — hard to reach one-handed
        .buttonStyle(.borderedProminent)
        .padding()
    ScrollView { /* content */ }
}

Rule 1.4: Support All iPhone Screen Sizes

Design for iPhone SE (375pt wide) through iPhone Pro Max (430pt wide). Use flexible layouts, avoid hardcoded widths.

Correct:

HStack(spacing: 12) {
    ForEach(items) { item in
        CardView(item: item)
            .frame(maxWidth: .infinity) // Adapts to screen width
    }
}

Incorrect:

HStack(spacing: 12) {
    ForEach(items) { item in
        CardView(item: item)
            .frame(width: 180) // Breaks on SE, wastes space on Pro Max
    }
}

Rule 1.5: 8pt Grid Alignment

Align spacing, padding, and element sizes to multiples of 8 points (8, 16, 24, 32, 40, 48). Use 4pt for fine adjustments.

Rule 1.6: Landscape Support

Support landscape orientation unless the app is task-specific (e.g., camera). Use ViewThatFits or GeometryReader for adaptive layouts.

2. Navigation

Impact: CRITICAL

Rule 2.1: Tab Bar for Top-Level Sections

Use a tab bar at the bottom of the screen for 3 to 5 top-level sections. Each tab should represent a distinct category of content or functionality.

Correct:

TabView {
    HomeView()
        .tabItem {
            Label("Home", systemImage: "house")
        }
    SearchView()
        .tabItem {
            Label("Search", systemImage: "magnifyingglass")
        }
    ProfileView()
        .tabItem {
            Label("Profile", systemImage: "person")
        }
}

Incorrect:

// Hamburger menu hidden behind three lines — discoverability is near zero
NavigationView {
    Button(action: { showMenu.toggle() }) {
        Image(systemName: "line.horizontal.3")
    }
}

Rule 2.2: Never Use Hamburger Menus

Hamburger (drawer) menus hide navigation, reduce discoverability, and violate iOS conventions. Use a tab bar instead. If you have more than 5 sections, consolidate or use a "More" tab.

Rule 2.3: Large Titles in Primary Views

Use .navigationBarTitleDisplayMode(.large) for top-level views. Titles transition to inline (.inline) when the user scrolls.

Correct:

NavigationStack {
    List(items) { item in
        ItemRow(item: item)
    }
    .navigationTitle("Messages")
    .navigationBarTitleDisplayMode(.large)
}

Rule 2.4: Never Override Back Swipe

The swipe-from-left-edge gesture for back navigation is a system-level expectation. Never attach custom gesture recognizers that interfere with it.

Incorrect:

.gesture(
    DragGesture()
        .onChanged { /* custom drawer */ } // Conflicts with system back swipe
)

Rule 2.5: Use NavigationStack for Hierarchical Content

Use NavigationStack (not the deprecated NavigationView) for drill-down content. Use NavigationPath for programmatic navigation.

Correct:

NavigationStack(path: $path) {
    List(items) { item in
        NavigationLink(value: item) {
            ItemRow(item: item)
        }
    }
    .navigationDestination(for: Item.self) { item in
        ItemDetail(item: item)
    }
}

Rule 2.6: Preserve State Across Navigation

When users navigate back and then forward, or switch tabs, restore the previous scroll position and input state. Use @SceneStorage or @State to persist view state.

Rule 2.7: Prefer Recognition Over Recall

3. Typography & Dynamic Type

Impact: HIGH

Rule 3.1: Use Built-in Text Styles

Always use semantic text styles rather than hardcoded sizes. These scale automatically with Dynamic Type.

Correct:

VStack(alignment: .leading, spacing: 4) {
    Text("Section Title")
        .font(.headline)
    Text("Body content that explains the section.")
        .font(.body)
    Text("Last updated 2 hours ago")
        .font(.caption)
        .foregroundStyle(.secondary)
}

Incorrect:

VStack(alignment: .leading, spacing: 4) {
    Text("Section Title")
        .font(.system(size: 17, weight: .semibold)) // Won't scale with Dynamic Type
    Text("Body content")
        .font(.system(size: 15)) // Won't scale with Dynamic Type
}

Rule 3.2: Support Dynamic Type Including Accessibility Sizes

Dynamic Type can scale text up to approximately 200% at the largest accessibility sizes. Layouts must reflow — never truncate or clip essential text.

Correct:

HStack {
    Image(systemName: "star")
    Text("Favorites")
        .font(.body)
}
// At accessibility sizes, consider using ViewThatFits or
// AnyLayout to switch from HStack to VStack

Use @Environment(\.dynamicTypeSize) to detect size category and adapt layouts:

@Environment(\.dynamicTypeSize) var dynamicTypeSize

var body: some View {
    if dynamicTypeSize.isAccessibilitySize {
        VStack { content }
    } else {
        HStack { content }
    }
}

Rule 3.3: Custom Fonts Must Scale with Dynamic Type

If you use a custom typeface, scale it so it responds to Dynamic Type. The API differs by framework.

Correct (SwiftUI):

extension Font {
    static func scaledCustom(size: CGFloat, relativeTo textStyle: Font.TextStyle) -> Font {
        .custom("CustomFont-Regular", size: size, relativeTo: textStyle)
    }
}

// Usage
Text("Hello")
    .font(.scaledCustom(size: 17, relativeTo: .body))

Correct (UIKit):

let metrics = UIFontMetrics(forTextStyle: .body)
let customFont = UIFont(name: "CustomFont-Regular", size: 17)!
label.font = metrics.scaledFont(for: customFont)
label.adjustsFontForContentSizeCategory = true

Rule 3.4: SF Pro as System Font

Use the system font (SF Pro) unless brand requirements dictate otherwise. SF Pro is optimized for legibility on Apple displays.

Rule 3.5: Minimum 11pt Text

Never display text smaller than 11pt. Prefer 17pt for body text. Use the caption2 style (11pt) as the absolute minimum.

Rule 3.6: Hierarchy Through Weight and Size

Establish visual hierarchy through font weight and size. Do not rely solely on color to differentiate text levels.

4. Color & Dark Mode

Impact: HIGH

Rule 4.1: Use Semantic System Colors

Use system-provided semantic colors that automatically adapt to light and dark modes.

Correct:

Text("Primary text")
    .foregroundStyle(.primary) // Adapts to light/dark

Text("Secondary info")
    .foregroundStyle(.secondary)

VStack { }
    .background(Color(.systemBackground)) // White in light, black in dark

Incorrect:

Text("Primary text")
    .foregroundColor(.black) // Invisible on dark backgrounds

VStack { }
    .background(.white) // Blinding in Dark Mode

Rule 4.2: Provide Light and Dark Variants for Custom Colors

Define custom colors in the asset catalog with both Any Appearance and Dark Appearance variants.

// In Assets.xcassets, define "BrandBlue" with:
// Any Appearance: #0066CC
// Dark Appearance: #4DA3FF

Text("Brand text")
    .foregroundStyle(Color("BrandBlue")) // Automatically switches

Rule 4.3: Never Rely on Color Alone

Always pair color with text, icons, or shapes to convey meaning. Approximately 8% of men have some form of color vision deficiency.

Correct:

HStack {
    Image(systemName: "exclamationmark.triangle.fill")
        .foregroundStyle(.red)
    Text("Error: Invalid email address")
        .foregroundStyle(.red)
}

Incorrect:

// Only color indicates the error — invisible to colorblind users
TextField("Email", text: $email)
    .border(isValid ? .green : .red)

Rule 4.4: 4.5:1 Contrast Ratio Minimum

All text must meet WCAG AA contrast ratios: 4.5:1 for normal text, 3:1 for large text (18pt+ or 14pt+ bold).

Rule 4.5: Support Display P3 Wide Gamut

Use Display P3 color space for vibrant, accurate colors on modern iPhones. Define colors in the asset catalog with the Display P3 gamut.

Rule 4.6: Background Hierarchy

Use the three-level background hierarchy for depth:

systemBackground — primary surface
secondarySystemBackground — grouped content, cards
tertiarySystemBackground — elements within grouped content

Rule 4.7: One Accent Color for Interactive Elements

Choose a single tint/accent color for all interactive elements (buttons, links, toggles). This creates a consistent, learnable visual language.

@main
struct MyApp: App {
    var body: some Scene {
        WindowGroup {
            ContentView()
                .tint(.indigo) // All interactive elements use indigo
        }
    }
}

5. Accessibility

Impact: CRITICAL

Rule 5.1: VoiceOver Labels on All Interactive Elements

Every button, control, and interactive element must have a meaningful accessibility label.

Correct:

Button(action: addToCart) {
    Image(systemName: "cart.badge.plus")
}
.accessibilityLabel("Add to cart")

Incorrect:

Button(action: addToCart) {
    Image(systemName: "cart.badge.plus")
}
// VoiceOver reads "cart.badge.plus" — meaningless to users

Rule 5.2: Logical VoiceOver Navigation Order

Ensure VoiceOver reads elements in a logical order. Use .accessibilitySortPriority() to adjust when the visual layout doesn't match the reading order.

VStack {
    Text("Price: $29.99")
        .accessibilitySortPriority(1) // Read second (lower number = lower priority)
    Text("Product Name")
        .accessibilitySortPriority(2) // Read first (higher number = higher priority)
}

Rule 5.3: Support Bold Text

Correct:

// SwiftUI — standard text styles adapt automatically
Text("Section Header")
    .font(.headline)

// SwiftUI — custom rendering respects legibilityWeight
@Environment(\.legibilityWeight) var legibilityWeight

var body: some View {
    Text("Custom Label")
        .fontWeight(legibilityWeight == .bold ? .bold : .regular)
}

Incorrect:

// Hardcoded weight ignores Bold Text preference
label.font = UIFont.systemFont(ofSize: 17, weight: .regular)
// Missing: re-query font when UIAccessibility.boldTextStatusDidChangeNotification fires

Rule 5.4: Support Reduce Motion

Disable decorative animations and parallax when Reduce Motion is enabled. Use @Environment(\.accessibilityReduceMotion).

Correct:

@Environment(\.accessibilityReduceMotion) var reduceMotion

var body: some View {
    CardView()
        .animation(reduceMotion ? nil : .spring(), value: isExpanded)
}

Rule 5.5: Support Increase Contrast

When the user enables Increase Contrast, ensure custom colors have higher-contrast variants. Use @Environment(\.colorSchemeContrast) to detect.

Rule 5.6: Don't Convey Info Only by Color, Shape, or Position

Information must be available through multiple channels. Pair visual indicators with text or accessibility descriptions.

Rule 5.7: Alternative Interactions for All Gestures

Every custom gesture must have an equivalent tap-based or menu-based alternative for users who cannot perform complex gestures.

Rule 5.8: Support Switch Control and Full Keyboard Access

Ensure all interactions work with Switch Control (external switches) and Full Keyboard Access (Bluetooth keyboards). Test navigation order and focus behavior.

6. Gestures & Input

Impact: HIGH

Rule 6.1: Use Standard Gestures

Use the standard iOS gesture vocabulary: tap, long press, swipe, pinch, rotate. Users already understand these.

Gesture	Standard Use
Tap	Primary action, selection
Long press	Context menu, preview
Swipe horizontal	Delete, archive, navigate back
Swipe vertical	Scroll, dismiss sheet
Pinch	Zoom in/out
Two-finger rotate	Rotate content

Rule 6.2: Never Override System Gestures

These gestures are reserved by the system and must not be intercepted:

Swipe from left edge (back navigation)
Swipe down from top-left (Notification Center)
Swipe down from top-right (Control Center)
Swipe up from bottom (home / app switcher)

Rule 6.3: Custom Gestures Must Be Discoverable

If you add a custom gesture, provide visual hints (e.g., a grabber handle) and ensure the action is also available through a visible button or menu item.

Rule 6.4: Support All Input Methods

Design for touch first, but also support:

Hardware keyboards (iPad keyboard accessories, Bluetooth keyboards)
Assistive devices (Switch Control, head tracking)
Pointer input (assistive touch)

7. Components

Impact: HIGH

Rule 7.1: Button Styles

Use the built-in button styles appropriately:

.borderedProminent — primary call-to-action
.bordered — secondary actions
.borderless — tertiary or inline actions
.destructive role — red tint for delete/remove

Correct:

VStack(spacing: 16) {
    Button("Purchase") { buy() }
        .buttonStyle(.borderedProminent)

    Button("Add to Wishlist") { wishlist() }
        .buttonStyle(.bordered)

    Button("Delete", role: .destructive) { delete() }
}

Rule 7.2: Alerts — Critical Info Only

Use alerts sparingly for critical information that requires a decision. Prefer 2 buttons; maximum 3. The destructive option should use .destructive role.

Correct:

.alert("Delete Photo?", isPresented: $showAlert) {
    Button("Delete", role: .destructive) { deletePhoto() }
    Button("Cancel", role: .cancel) { }
} message: {
    Text("This photo will be permanently removed.")
}

Incorrect:

// Alert for non-critical info — should be a banner or toast
.alert("Tip", isPresented: $showTip) {
    Button("OK") { }
} message: {
    Text("Swipe left to delete items.")
}

Rule 7.3: Sheets for Scoped Tasks

Present sheets for self-contained tasks. Always provide a way to dismiss (close button or swipe down). Use .presentationDetents() for half-height sheets.

.sheet(isPresented: $showCompose) {
    NavigationStack {
        ComposeView()
            .navigationTitle("New Message")
            .toolbar {
                ToolbarItem(placement: .cancellationAction) {
                    Button("Cancel") { showCompose = false }
                }
                ToolbarItem(placement: .confirmationAction) {
                    Button("Send") { send() }
                }
            }
    }
    .presentationDetents([.medium, .large])
}

Rule 7.4: Lists — Inset Grouped Default

Use the .insetGrouped list style as the default. Support swipe actions for common operations. Minimum row height is 44pt.

Correct:

List {
    Section("Recent") {
        ForEach(recentItems) { item in
            ItemRow(item: item)
                .swipeActions(edge: .trailing) {
                    Button(role: .destructive) { delete(item) } label: {
                        Label("Delete", systemImage: "trash")
                    }
                    Button { archive(item) } label: {
                        Label("Archive", systemImage: "archivebox")
                    }
                    .tint(.blue)
                }
        }
    }
}
.listStyle(.insetGrouped)

Rule 7.5: Tab Bar Behavior

Use SF Symbols for tab icons — filled variant for the selected tab, outline for unselected
Never hide the tab bar when navigating deeper within a tab
Badge important counts with .badge()

TabView {
    MessagesView()
        .tabItem {
            Label("Messages", systemImage: "message")
        }
        .badge(unreadCount)
}

Rule 7.6: Search

Place search using .searchable(). Provide search suggestions and support recent searches.

NavigationStack {
    List(filteredItems) { item in
        ItemRow(item: item)
    }
    .searchable(text: $searchText, prompt: "Search items")
    .searchSuggestions {
        ForEach(suggestions) { suggestion in
            Text(suggestion.title)
                .searchCompletion(suggestion.title)
        }
    }
}

Rule 7.7: Context Menus

Use context menus (long press) for secondary actions. Never use a context menu as the only way to access an action.

PhotoView(photo: photo)
    .contextMenu {
        Button { share(photo) } label: {
            Label("Share", systemImage: "square.and.arrow.up")
        }
        Button { favorite(photo) } label: {
            Label("Favorite", systemImage: "heart")
        }
        Button(role: .destructive) { delete(photo) } label: {
            Label("Delete", systemImage: "trash")
        }
    }

Rule 7.8: Progress Indicators

Determinate (ProgressView(value:total:)) for operations with known duration
Indeterminate (ProgressView()) for unknown duration
Never block the entire screen with a spinner

Rule 7.9: SF Symbols — Rendering Modes

Correct:

// Hierarchical: single color with automatic opacity layers
Image(systemName: "person.crop.circle.fill")
    .symbolRenderingMode(.hierarchical)
    .foregroundStyle(.blue)

// Multicolor: system-defined color per layer (e.g., battery, weather)
Image(systemName: "battery.100percent.bolt")
    .symbolRenderingMode(.multicolor)

// Palette: explicit per-layer colors
Image(systemName: "folder.badge.plus")
    .symbolRenderingMode(.palette)
    .foregroundStyle(.white, .blue)

Incorrect:

// Monochrome on a symbol that has meaningful multicolor layers
Image(systemName: "battery.100percent.bolt")
    .foregroundColor(.gray) // loses the contextual color meaning

Rule 7.10: SF Symbols — Weight and Scale

Match the symbol weight to adjacent text weight. Use scale variants (.small, .medium, .large) rather than resizing. The symbol weight should never appear heavier than adjacent text.

Correct:

Label("Download", systemImage: "arrow.down.circle.fill")
    .font(.body.weight(.semibold))
    // Symbol inherits .semibold weight automatically via Label

Incorrect:

HStack {
    Image(systemName: "arrow.down.circle.fill")
        .font(.system(size: 32)) // explicit size ignores type scale
    Text("Download")
        .font(.body)
}

Rule 7.11: SF Symbols — Animations (iOS 17+)

Correct:

Image(systemName: isLoading ? "arrow.2.circlepath" : "checkmark.circle")
    .contentTransition(.symbolEffect(.replace))
    .symbolEffect(.pulse, isActive: isLoading)

Incorrect:

// Manual opacity cross-fade between symbol names
if isLoading {
    Image(systemName: "arrow.2.circlepath")
} else {
    Image(systemName: "checkmark.circle")
}

8. Patterns

Impact: MEDIUM

Rule 8.1: Onboarding — Max 3 Pages, Skippable

Keep onboarding to 3 or fewer pages. Always provide a skip option. Defer sign-in until the user needs authenticated features.

TabView {
    OnboardingPage(
        image: "wand.and.stars",
        title: "Smart Suggestions",
        subtitle: "Get personalized recommendations based on your preferences."
    )
    OnboardingPage(
        image: "bell.badge",
        title: "Stay Updated",
        subtitle: "Receive notifications for things that matter to you."
    )
    OnboardingPage(
        image: "checkmark.shield",
        title: "Private & Secure",
        subtitle: "Your data stays on your device."
    )
}
.tabViewStyle(.page)
.overlay(alignment: .topTrailing) {
    Button("Skip") { completeOnboarding() }
        .padding()
}

Rule 8.2: Loading — Skeleton Views, No Blocking Spinners

Use skeleton/placeholder views that match the layout of the content being loaded. Never show a full-screen blocking spinner.

Correct:

if isLoading {
    ForEach(0..<5) { _ in
        SkeletonRow() // Placeholder matching final row layout
            .redacted(reason: .placeholder)
    }
} else {
    ForEach(items) { item in
        ItemRow(item: item)
    }
}

Incorrect:

if isLoading {
    ProgressView("Loading...") // Blocks the entire view
} else {
    List(items) { item in ItemRow(item: item) }
}

Rule 8.3: Launch Screen — Match First Screen

The launch storyboard must visually match the initial screen of the app. No splash logos, no branding screens. This creates the perception of instant launch.

Rule 8.4: Modality — Use Sparingly

Present modal views only when the user must complete or abandon a focused task. Always provide a clear dismiss action. Never stack modals on top of modals.

Rule 8.5: Notifications — High Value Only

Only send notifications for content the user genuinely cares about. Support actionable notifications. Categorize notifications so users can control them granularly.

Rule 8.6: Settings Placement

Frequent settings: In-app settings screen accessible from a profile or gear icon
Privacy/permission settings: Defer to the system Settings app via URL scheme
Never duplicate system-level controls in-app

Rule 8.7: Feedback — Visual + Haptic

Provide immediate feedback for every user action:

Visual state change (button highlight, animation)
Haptic feedback for significant actions using UIImpactFeedbackGenerator, UINotificationFeedbackGenerator, or UISelectionFeedbackGenerator

Button("Complete") {
    let generator = UINotificationFeedbackGenerator()
    generator.notificationOccurred(.success)
    completeTask()
}

Rule 8.8: Show Waiting States Immediately

If an action cannot complete immediately, acknowledge the tap at once, then show inline progress, skeletons, or partial results. Never leave the interface visually unchanged while work continues.

9. Privacy & Permissions

Impact: HIGH

Rule 9.1: Request Permissions in Context

Request a permission at the moment the user takes an action that needs it — never at app launch.

Correct:

Button("Take Photo") {
    // Request camera permission only when the user taps this button
    AVCaptureDevice.requestAccess(for: .video) { granted in
        if granted { showCamera = true }
    }
}

Incorrect:

// In AppDelegate.didFinishLaunching — too early, no context
func application(_ application: UIApplication, didFinishLaunchingWithOptions ...) {
    AVCaptureDevice.requestAccess(for: .video) { _ in }
    CLLocationManager().requestWhenInUseAuthorization()
    UNUserNotificationCenter.current().requestAuthorization(options: [.alert]) { _, _ in }
}

Rule 9.2: Explain Before System Prompt

Show a custom explanation screen before triggering the system permission dialog. The system dialog only appears once — if the user denies, the app must direct them to Settings.

struct LocationExplanation: View {
    var body: some View {
        VStack(spacing: 16) {
            Image(systemName: "location.fill")
                .font(.largeTitle)
            Text("Find Nearby Stores")
                .font(.headline)
            Text("We use your location to show stores within walking distance. Your location is never shared or stored.")
                .font(.body)
                .multilineTextAlignment(.center)
            Button("Enable Location") {
                locationManager.requestWhenInUseAuthorization()
            }
            .buttonStyle(.borderedProminent)
            Button("Not Now") { dismiss() }
                .foregroundStyle(.secondary)
        }
        .padding()
    }
}

Rule 9.3: Support Sign in with Apple

If the app offers any third-party sign-in (Google, Facebook), it must also offer Sign in with Apple. Present it as the first option.

Rule 9.4: Don't Require Accounts Unless Necessary

Let users explore the app before requiring sign-in. Gate only features that genuinely need authentication (purchases, sync, social features).

Rule 9.5: App Tracking Transparency

If you track users across apps or websites, display the ATT prompt. Respect denial — do not degrade the experience for users who opt out.

Rule 9.6: Location Button for One-Time Access

Use LocationButton for actions that need location once without requesting ongoing permission.

import CoreLocationUI

LocationButton(.currentLocation) {
    fetchNearbyStores()
}
.labelStyle(.titleAndIcon)

10. System Integration

Impact: MEDIUM

Rule 10.1: Widgets for Glanceable Data

// iOS 17+ interactive widget with a Button
struct TimerWidgetView: View {
    let entry: TimerEntry

    var body: some View {
        VStack {
            Text(entry.remaining, style: .timer)
                .font(.title2.bold())
            Button(intent: ToggleTimerIntent()) {
                Label(entry.isRunning ? "Pause" : "Start",
                      systemImage: entry.isRunning ? "pause.fill" : "play.fill")
            }
            .buttonStyle(.borderedProminent)
        }
    }
}

Rule 10.2: App Shortcuts for Key Actions

Define App Shortcuts so users can trigger key actions from Siri, Spotlight, and the Shortcuts app.

struct MyAppShortcuts: AppShortcutsProvider {
    static var appShortcuts: [AppShortcut] {
        AppShortcut(
            intent: StartWorkoutIntent(),
            phrases: ["Start a workout in \(.applicationName)"],
            shortTitle: "Start Workout",
            systemImageName: "figure.run"
        )
    }
}

Rule 10.3: Spotlight Indexing

Index app content with CSSearchableItem so users can find it from Spotlight search.

Rule 10.4: Share Sheet Integration

Support the system share sheet for content that users might want to send elsewhere. Implement UIActivityItemSource or use ShareLink in SwiftUI.

ShareLink(item: article.url) {
    Label("Share", systemImage: "square.and.arrow.up")
}

Rule 10.5: Live Activities

Use Live Activities and the Dynamic Island for real-time, time-bound events (delivery tracking, sports scores, workouts).

Rule 10.6: Handle Interruptions Gracefully

Save state and pause gracefully when interrupted by:

Phone calls
Siri invocations
Notifications
App switcher
FaceTime SharePlay

Use scenePhase to detect transitions:

@Environment(\.scenePhase) var scenePhase

.onChange(of: scenePhase) { _, newPhase in
    switch newPhase {
    case .active: resumeActivity()
    case .inactive: pauseActivity()
    case .background: saveState()
    @unknown default: break
    }
}

Quick Reference

Need	Component	Notes
Top-level sections (3-5)	`TabView` with `.tabItem`	Bottom tab bar, SF Symbols
Hierarchical drill-down	`NavigationStack`	Large title on root, inline on children
Self-contained task	`.sheet`	Swipe to dismiss, cancel/done buttons
Critical decision	`.alert`	2 buttons preferred, max 3
Secondary actions	`.contextMenu`

Evaluation Checklist

Use this checklist to audit an iPhone app for HIG compliance:

Layout & Safe Areas

All touch targets are at least 44x44pt
No content is clipped under status bar, Dynamic Island, or home indicator
Primary actions are in the bottom half of the screen (thumb zone)
Layout adapts from iPhone SE to Pro Max without breaking
Spacing aligns to the 8pt grid

Navigation

Tab bar is used for 3-5 top-level sections
No hamburger/drawer menus
Primary views use large titles
Swipe-from-left-edge back navigation works throughout
State is preserved when switching tabs

Typography

All text uses built-in text styles or custom fonts scaled with Dynamic Type (Font.custom(_:size:relativeTo:) in SwiftUI or UIFontMetrics in UIKit)
Dynamic Type is supported up to accessibility sizes
Layouts reflow at large text sizes (no truncation of essential text)
Minimum text size is 11pt

Color & Dark Mode

App uses semantic system colors or provides light/dark asset variants
Dark Mode looks intentional (not just inverted)
No information conveyed by color alone
Text contrast meets 4.5:1 (normal) or 3:1 (large)
Single accent color for interactive elements

Accessibility

VoiceOver reads all screens logically with meaningful labels
Bold Text preference is respected
Reduce Motion disables decorative animations
Increase Contrast variant exists for custom colors
All gestures have alternative access paths

Components

Alerts are used only for critical decisions
Sheets have a dismiss path (button and/or swipe)
List rows are at least 44pt tall
Tab bar is never hidden during navigation
Destructive buttons use the .destructive role

Privacy

Permissions are requested in context, not at launch
Custom explanation shown before each system permission dialog
Sign in with Apple offered alongside other providers
App is usable without an account for basic features
ATT prompt is shown if tracking, and denial is respected

System Integration

Widgets show glanceable, up-to-date information
App content is indexed for Spotlight
Share Sheet is available for shareable content
App handles interruptions (calls, background, Siri) gracefully

Anti-Patterns

These are common mistakes that violate the iOS Human Interface Guidelines. Never do these:

Hamburger menus — Use a tab bar. Hamburger menus hide navigation and reduce feature discoverability by up to 50%.
Custom back buttons that break swipe-back — If you replace the back button, ensure the swipe-from-left-edge gesture still works via NavigationStack.
Full-screen blocking spinners — Use skeleton views or inline progress indicators. Blocking spinners make the app feel frozen.
Splash screens with logos — The launch screen must mirror the first screen of the app. Branding delays feel artificial.
Requesting all permissions at launch — Asking for camera, location, notifications, and contacts on first launch guarantees most will be denied.
Hardcoded font sizes — Use text styles. Hardcoded sizes ignore Dynamic Type and accessibility preferences, breaking the app for millions of users.
Using only color to indicate state — Red/green for valid/invalid excludes colorblind users. Always pair with icons or text.
Alerts for non-critical information — Alerts interrupt flow and require dismissal. Use banners, toasts, or inline messages for tips and non-critical information.
Hiding the tab bar on push — Tab bars should remain visible throughout navigation within a tab. Hiding them disorients users.
Ignoring safe areas — Using .ignoresSafeArea() on content views causes text and buttons to disappear under the notch, Dynamic Island, or home indicator.