What Are the Human Interface Guidelines?
Apple's Human Interface Guidelines (HIG) are a comprehensive design manual that defines how iOS, iPadOS, macOS, watchOS, tvOS, and visionOS apps should look, feel, and behave. First published alongside the original Macintosh in 1984, the HIG has evolved into one of the most influential design documents in software.
For mobile developers, the HIG is not just a suggestion. It is the standard Apple uses to evaluate apps during App Store review. Apps that ignore HIG principles face rejection, poor ratings, or user churn because the app "feels wrong" compared to the rest of the system.
Why HIG Compliance Matters
There are three practical reasons to follow the HIG:
- App Store approval - Apple rejects apps that deviate significantly from platform conventions. Non-standard tab bars, custom alert dialogs, or broken back gestures trigger rejections.
- User trust - iOS users expect consistent behavior across apps. When your app uses standard patterns, users already know how to navigate without a tutorial.
- Future compatibility - Apps built with HIG-compliant system components automatically adapt to new iOS versions, Dynamic Island, and accessibility features without code changes.
Core HIG Principles
Clarity: Every element on screen should serve a clear purpose. Text must be legible at every size. Icons should be precise and immediately understandable. Whitespace is a tool, not wasted space.
Deference: The interface should help people understand and interact with content, but never compete with it. Translucent backgrounds, system fonts, and restrained color usage let content take center stage.
Depth: Visual layers and realistic motion create hierarchy. iOS uses a layered system where sheets slide over content, popovers float above the interface, and blur effects communicate what sits behind the current view.
Key HIG Components for iOS in 2026
| Component | HIG Recommendation | Common Mistake |
|---|---|---|
| Navigation Bar | System UINavigationBar with large titles | Custom header that loses swipe-back gesture |
| Tab Bar | Maximum 5 tabs, use SF Symbols | More than 5 tabs, custom icon style |
| Sheets | Use .medium and .large detents | Full-screen modals for simple tasks |
| Typography | Use Dynamic Type with system fonts | Fixed font sizes that break accessibility |
| Colors | Support both light and dark with semantic colors | Hardcoded hex values ignoring appearance |
SF Symbols
Apple provides over 6,000 SF Symbols in 2026, covering virtually every common interface need. HIG strongly recommends SF Symbols over custom icons because they support all weight variants, Dynamic Type scaling, accessibility features like Bold Text, right-to-left localization, and variable color animation.
Common HIG Violations That Cause Rejections
Custom alert dialogs: Replacing UIAlertController with a custom popup is a frequent rejection reason. Apple wants alerts to look consistent. Use a sheet for richer content instead.
Non-standard gestures: Overriding the system back swipe or requiring unusual multi-finger gestures triggers rejection. Always ensure custom gestures do not conflict with iOS system gestures.
Ignoring safe areas: With Dynamic Island and various screen shapes, respecting safe area insets is non-negotiable. Content must never be clipped by hardware elements.
Missing dark mode: Since iOS 13, Apple expects dark mode support. Not supporting it affects App Store featuring and user experience.
HIG and SwiftUI
SwiftUI makes HIG compliance the default behavior. Standard components automatically provide correct spacing, Dynamic Type support, dark mode adaptation, and accessibility labels. This is a strong argument for SwiftUI adoption: doing the right thing is easier than doing the wrong thing.
Cross-Platform Developers
If you use React Native or Flutter, HIG compliance requires extra attention. Use platform-specific navigation components, implement iOS gestures (swipe back, pull to refresh), use SF Symbols on iOS, and always test on actual devices. Apple updates the HIG at every WWDC, so bookmark developer.apple.com/design/human-interface-guidelines.