# HIG: Typography

Source: [Apple HIG — Typography](https://developer.apple.com/design/human-interface-guidelines/typography)

## System Fonts

- **San Francisco (SF):** SF Pro, SF Compact, SF Mono, SF Arabic, SF Armenian, SF Georgian, SF Hebrew — plus Rounded variants
- **New York (NY):** Serif family, works well alongside SF
- Variable font format with dynamic optical sizes — no need to pick discrete optical sizes

## Default & Minimum Text Sizes

| Platform | Default | Minimum |
|----------|---------|---------|
| iOS, iPadOS | 17 pt | 11 pt |
| macOS | 13 pt | 10 pt |
| tvOS | 29 pt | 23 pt |
| visionOS | 17 pt | 12 pt |
| watchOS | 16 pt | 12 pt |

## Text Styles (iOS/iPadOS — Large/Default)

| Style | Weight | Size | Leading | Emphasized |
|-------|--------|------|---------|------------|
| Large Title | Regular | 34 pt | 41 pt | Bold |
| Title 1 | Regular | 28 pt | 34 pt | Bold |
| Title 2 | Regular | 22 pt | 28 pt | Bold |
| Title 3 | Regular | 20 pt | 25 pt | Semibold |
| Headline | Semibold | 17 pt | 22 pt | Semibold |
| Body | Regular | 17 pt | 22 pt | Semibold |
| Callout | Regular | 16 pt | 21 pt | Semibold |
| Subhead | Regular | 15 pt | 20 pt | Semibold |
| Footnote | Regular | 13 pt | 18 pt | Semibold |
| Caption 1 | Regular | 12 pt | 16 pt | Semibold |
| Caption 2 | Regular | 11 pt | 13 pt | Semibold |

## macOS Text Styles

| Style | Weight | Size | Line Height | Emphasized |
|-------|--------|------|-------------|------------|
| Large Title | Regular | 26 pt | 32 pt | Bold |
| Title 1 | Regular | 22 pt | 26 pt | Bold |
| Title 2 | Regular | 17 pt | 22 pt | Bold |
| Title 3 | Regular | 15 pt | 20 pt | Semibold |
| Headline | Bold | 13 pt | 16 pt | Heavy |
| Body | Regular | 13 pt | 16 pt | Semibold |
| Callout | Regular | 12 pt | 15 pt | Semibold |
| Subheadline | Regular | 11 pt | 14 pt | Semibold |
| Footnote | Regular | 10 pt | 13 pt | Semibold |
| Caption 1 | Regular | 10 pt | 13 pt | Medium |
| Caption 2 | Medium | 10 pt | 13 pt | Semibold |

## tvOS Text Styles

| Style | Weight | Size | Leading | Emphasized |
|-------|--------|------|---------|------------|
| Title 1 | Medium | 76 pt | 96 pt | Bold |
| Title 2 | Medium | 57 pt | 66 pt | Bold |
| Title 3 | Medium | 48 pt | 56 pt | Bold |
| Headline | Medium | 38 pt | 46 pt | Bold |
| Subtitle 1 | Regular | 38 pt | 46 pt | Medium |
| Callout | Medium | 31 pt | 38 pt | Bold |
| Body | Medium | 29 pt | 36 pt | Bold |
| Caption 1 | Medium | 25 pt | 32 pt | Bold |
| Caption 2 | Medium | 23 pt | 30 pt | Bold |

## Best Practices

- Avoid light font weights (Ultralight, Thin, Light) — prefer Regular, Medium, Semibold, Bold
- Minimize the number of typefaces — too many obscures hierarchy
- Use `bold()` in SwiftUI (not `fontWeight(.bold)`) so the system picks context-appropriate weight
- Use `Font.Design.default` for system font, `Font.Design.serif` for New York
- Don't embed system fonts — use the APIs

## Dynamic Type

- System-level feature in iOS, iPadOS, tvOS, visionOS, watchOS
- Text styles scale proportionately when people change text size
- Support Larger Accessibility Text Sizes (AX1-AX5 go up to 60pt body)
- Consider adjusting layout at large sizes (stack horizontally placed items vertically)
- Keep text truncation minimal — display as much useful text as possible
- Maintain consistent information hierarchy regardless of font size
- Use `isAccessibilityCategory` to detect when accessibility sizes are active

## Custom Fonts

- Always use `relativeTo:` with `.font(.custom())` to support Dynamic Type
- Use `@ScaledMetric` (iOS 18-) or `.font(.body.scaled(by:))` (iOS 26+) for custom sizing
- Implement accessibility features (Bold Text, Dynamic Type) for custom fonts

## visionOS Specifics

- Uses bolder body and title styles, plus Extra Large Title 1 and 2
- Prefer 2D text — 3D text is harder to read
- Use billboarding for text associated with spatial objects
- Maximize contrast between text and container background

## Tracking Values (SF Pro — Key Sizes)

| Size | Tracking (pt) |
|------|--------------|
| 11 pt | +0.06 |
| 12 pt | 0.0 |
| 13 pt | -0.08 |
| 17 pt (body) | -0.43 |
| 22 pt | -0.26 |
| 28 pt | +0.38 |
| 34 pt | +0.40 |
| 48 pt | +0.35 |
| 72 pt | +0.14 |
| 96 pt | 0.0 |