Apple HIG SwiftUI iOS 26 / Swift 6.2 Best Practices

A principal designer's lens for evaluating and refactoring SwiftUI interfaces to Apple-quality standards, grounded in Rams, Segall, and Edson. Contains 51 rules across 8 categories, each grounded in specific principles from three foundational design texts:

Dieter Rams — Ten Principles for Good Design ("less, but better," "design should be honest")
Ken Segall — Insanely Simple (simplicity as a core principle for intuitive, beautiful products)
John Edson — Design Like Apple (design-focused culture, prototyping to perfection, the product is the marketing)

Categories are ordered by a visual review process: start with what to remove, then what to clarify, then what to make honest, invisible, systematic, thorough, enduring, and finally what to refine.

Scope & Relationship to Sibling Skills

This skill is the refactoring and review lens — it evaluates existing UI and identifies visual anti-patterns to fix. When loaded alongside

ios-design

(building new UI),

ios-hig

(HIG compliance), or

swift-refactor

(code-level refactoring), this skill supersedes overlapping rules with more detailed "incorrect -> correct" transformations and "When NOT to apply" guidance. Use this skill for auditing and improving existing screens; use the siblings for greenfield implementation.

Clinic Architecture Contract (iOS 26 / Swift 6.2)

All guidance in this skill assumes the clinic modular MVVM-C architecture:

Feature modules import
```
Domain
```
+
```
DesignSystem
```
only (never
```
Data
```
, never sibling features)
App target is the convergence point and owns
```
DependencyContainer
```
, concrete coordinators, and Route Shell wiring
```
Domain
```
stays pure Swift and defines models plus repository,
```
*Coordinating
```
,
```
ErrorRouting
```
, and
```
AppError
```
contracts
```
Data
```
owns SwiftData/network/sync/retry/background I/O and implements Domain protocols
Read/write flow defaults to stale-while-revalidate reads and optimistic queued writes
ViewModels call repository protocols directly (no default use-case/interactor layer)

When to Apply

Reference these guidelines when:

Reviewing existing SwiftUI screens for visual quality issues
Auditing whether every element on screen earns its place (Rams #10)
Evaluating if the interface is self-explanatory without tooltips (Rams #4)
Checking that colors, states, and hierarchy tell the truth (Rams #6)
Ensuring animations and materials are invisible, not decorative (Rams #5)
Verifying spacing, radii, and colors form a coherent system (Edson "Systems Thinking")
Confirming edge cases — reduce motion, touch targets, safe areas — are handled (Rams #8)
Adopting iOS 26 / Swift 6.2 APIs that refine previously impossible interactions (Edson "Design Out Loud")

Rule Categories by Priority


less-
evident-
honest-
invisible-
system-
thorough-
enduring-
refined-

Priority	Category	Principle	Impact	Prefix	Rules
1	Less, But Better	Rams #10 + Segall "Think Minimal"	CRITICAL	`less-`	7
2	Self-Evident Design	Rams #4 + Segall "Think Human"	CRITICAL	`evident-`	6
3	Honest Interfaces	Rams #6 + Segall "Think Brutal"	CRITICAL	`honest-`	6
4	Invisible Design	Rams #5 + Edson "Product Is Marketing"	HIGH	`invisible-`	6
5	Systems, Not Pieces	Edson "Systems Thinking" + Rams #8	HIGH	`system-`	6
6	Thorough to the Last Detail	Rams #8 + Rams #2	HIGH	`thorough-`	7
7	Enduring Over Trendy	Rams #7 + Edson "Design With Conviction"	MEDIUM-HIGH	`enduring-`	5
8	Refined Through Iteration	Edson "Design Out Loud" + Rams #1/#3	MEDIUM	`refined-`	8

Quick Reference

1. Less, But Better (CRITICAL)

Rams #10: "Good design is as little design as possible." Segall: Apple succeeded by saying no to a thousand things.

```
less-single-focal
```
- One primary focal point per screen
```
less-type-restraint
```
- Limit to 3-4 distinct type treatments per screen
```
less-one-typeface
```
- One typeface per app, differentiate with weight and size
```
less-color-restraint
```
- Reserve saturated colors for small interactive elements
```
less-one-color-purpose
```
- Each semantic color serves exactly one purpose
```
less-purposeful-motion
```
- Every animation must communicate state change or provide feedback
```
less-fewer-controls
```
- Remove controls that do not serve the core task

2. Self-Evident Design (CRITICAL)

Rams #4: "Good design makes a product understandable." Segall: interfaces must speak in terms people understand.

```
evident-visual-weight
```
- Combine size, weight, and contrast for hierarchy
```
evident-whitespace-grouping
```
- Use whitespace to separate conceptual groups
```
evident-progressive-disclosure
```
- Use progressive disclosure for dense information
```
evident-reading-order
```
- Align visual weight with logical reading order
```
evident-navigation-intent
```
- Sheets for tasks and creation, push for drill-down hierarchy
```
evident-label-clarity
```
- Use clear labels over ambiguous icons

3. Honest Interfaces (CRITICAL)

Rams #6: "Good design is honest." Segall: clarity without sugar-coating.

```
honest-semantic-colors
```
- Use semantic colors, never hard-coded black or white
```
honest-contrast
```
- Ensure WCAG AA contrast ratios
```
honest-dark-mode
```
- Define light and dark variants for every custom color
```
honest-foreground-style
```
- Use foregroundStyle over foregroundColor
```
honest-depth-cues
```
- Use materials for layering, not drop shadows for depth
```
honest-loading-states
```
- Show real progress, not indefinite spinners

4. Invisible Design (HIGH)

Rams #5: "Good design is unobtrusive." Edson: the product itself is the marketing.

```
invisible-spring-physics
```
- Default to spring animations for all UI transitions
```
invisible-spring-presets
```
- Use .smooth for routine, .snappy for interactive, .bouncy for delight
```
invisible-no-easing
```
- Prefer springs over linear and easeInOut for UI elements
```
invisible-system-materials
```
- Use system materials, not custom semi-transparent backgrounds
```
invisible-symbol-effects
```
- Use built-in symbolEffect, not manual symbol animation
```
invisible-content-transitions
```
- Use contentTransition for changing text and numbers

5. Systems, Not Pieces (HIGH)

Edson: "Design is systems thinking." Rams #8: nothing must be arbitrary or left to chance.

```
system-spacing-grid
```
- Use a 4pt base unit for all spacing
```
system-consistent-padding
```
- Use consistent padding across all screens
```
system-corner-radii
```
- Standardize corner radii per component type
```
system-alignment
```
- Consistent alignment per content type within a screen
```
system-color-naming
```
- Name custom colors by role, not hue
```
system-brand-integration
```
- Map brand palette onto iOS semantic color roles

6. Thorough to the Last Detail (HIGH)

Rams #8: "Care and accuracy in the design process show respect for the user." Rams #2: if the user cannot reliably use it, the product has failed.

```
thorough-reduce-motion
```
- Always provide reduce motion fallback
```
thorough-touch-targets
```
- All interactive elements at least 44x44 points
```
thorough-safe-areas
```
- Always respect safe areas
```
thorough-readable-weights
```
- Avoid light font weights for body text
```
thorough-vibrancy-levels
```
- Match vibrancy level to content importance
```
thorough-material-thickness
```
- Choose material thickness by contrast needs
```
thorough-background-interaction
```
- Enable background interaction for peek-style sheets

7. Enduring Over Trendy (MEDIUM-HIGH)

Rams #7: "Good design is long-lasting." Edson: commit to a voice that persists across product generations.

```
enduring-system-text-styles
```
- Use Apple text styles, never fixed font sizes
```
enduring-weight-not-caps
```
- Use weight for emphasis, not ALL CAPS
```
enduring-swipe-back
```
- Never break the system back-swipe gesture
```
enduring-zoom-navigation
```
- Use zoom transitions for collection-to-detail navigation
```
enduring-card-modularity
```
- Use self-contained cards for dashboard layouts

8. Refined Through Iteration (MEDIUM)

Edson: "Design out loud" — prototype relentlessly until every interaction feels inevitable. Rams #1: innovation serves genuine purpose.

```
refined-scroll-transitions
```
- Use scrollTransition for scroll-position visual effects
```
refined-phase-animator
```
- Use PhaseAnimator for multi-step animation sequences
```
refined-mesh-gradients
```
- Use MeshGradient for premium dynamic backgrounds
```
refined-text-renderer
```
- Use TextRenderer for hero text animations only
```
refined-inspector
```
- Use inspector for trailing-edge detail panels
```
refined-multi-detent
```
- Provide multiple sheet detents with drag indicator
```
refined-matched-geometry
```
- Use matchedGeometryEffect for contextual origin transitions
```
refined-no-hard-cuts
```
- Always animate between states, even minimally

How to Use

Read individual reference files for detailed explanations and code examples:

Section definitions - Category structure, principle sources, and impact levels
Rule template - Template for adding new rules

Reference Files

File	Description
references/_sections.md	Category definitions and principle grounding
assets/templates/_template.md	Template for new rules
metadata.json	Version and reference information

ios-ui-refactor

NPX Install

Tags

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