SwiftUIMarkdown

A zero-dependency SwiftUI markdown renderer for iOS 18, macOS 15, and beyond. Built on Foundation's AttributedString with PresentationIntent run-walking — no third-party parsers, no heavyweight abstractions.

Features

Full block-level rendering — headings H1–H6, paragraphs, ordered and unordered lists, code blocks, block quotes, tables, thematic breaks
Inline formatting — bold, italic, strikethrough, inline code, links
Zero dependencies — built entirely on Foundation and SwiftUI
Simple theming — one MarkdownTheme struct, no protocol hierarchies
Swift 6 strict concurrency — fully Sendable, safe across actors
Interactive playground — live editor + theme comparison built in

Quick Start

Add the package to your Package.swift:

dependencies: [
    .package(url: "https://github.com/onmyway133/swiftui-markdown", from: "1.0.0"),
],

Render markdown:

import SwiftUIMarkdown

struct ContentView: View {
    var body: some View {
        ScrollView {
            MarkdownView("""
            # Hello from SwiftUIMarkdown

            Render **bold**, *italic*, `code`, and [links](https://github.com/onmyway133).

            > Simple. Zero dependencies. Swift 6.
            """)
            .padding()
        }
    }
}

Inline-only text:

MarkdownLabel("Download the **latest** version [here](https://example.com).")

Block Type Support

Block	Syntax	Notes
Heading	`# H1` … `###### H6`	Levels 1–6
Paragraph	Plain text	Inline formatting supported
Unordered list	`- item`	Nested via indentation
Ordered list	`1. item`	Ordinal labels
Code block	```lang	Optional language caption
Block quote	`> text`	Left bar accent
Table	GFM pipe syntax	Header row bolded
Thematic break	`---`	Standard divider
Inline bold	`text`
Inline italic	`text`
Inline code	`code`	Themed color
Inline link	`[text](url)`	Accent color
Strikethrough	`~~text~~`

Theming

Apply a built-in preset:

MarkdownView(markdown)
    .markdownTheme(.github)

Customize by copy-and-modifying a preset:

var theme = MarkdownTheme.default
theme.headingColor = .purple
theme.quoteBarColor = .purple
theme.linkColor = .orange
theme.blockSpacing = 16

MarkdownView(markdown)
    .markdownTheme(theme)

MarkdownTheme properties:

Property	Type	Description
`headingFont`	`(Int) -> Font`	Font for heading levels 1–6
`headingColor`	`Color`	Heading text color
`bodyFont`	`Font`	Paragraph font
`bodyColor`	`Color`	Paragraph text color
`codeFont`	`Font`	Monospaced font for code
`codeBackground`	`Color`	Code block background fill
`codeForeground`	`Color`	Code text and inline code color
`quoteBarColor`	`Color`	Left bar color for block quotes
`quoteTextColor`	`Color`	Block quote text color
`linkColor`	`Color`	Hyperlink color
`blockSpacing`	`CGFloat`	Vertical gap between blocks

Example App

An Xcode project is included in Examples/MarkdownPreview/. It contains a three-tab iOS app:

Blocks — all supported block types rendered with the default theme
Themes — side-by-side comparison of .default and .github
Editor — live markdown editor with real-time preview

Open it directly:

open Examples/MarkdownPreview/MarkdownPreview.xcodeproj

The project references SwiftUIMarkdown as a local package (no network required). Each view in ContentView.swift also has #Preview macros for instant canvas rendering.

Architecture

MarkdownView(markdown)
      │
      ▼  AttributedString(markdown:, options: .full)
      │
      ▼  attrStr.blockGroups()       ← walks runs, groups by PresentationIntent identity
      │
      ▼  BlockRenderer               ← VStack dispatching on BlockGroup.Kind
      │
      ├─ HeadingBlockView            ← InlineRenderer.text() + themed font
      ├─ ParagraphBlockView          ← InlineRenderer.text() + body style
      ├─ ListBlockView               ← HStack(bullet, text) + depth indent
      ├─ CodeBlockView               ← ScrollView + monospaced + language caption
      ├─ QuoteBlockView              ← HStack(bar, text)
      ├─ TableBlockView              ← Grid + GridRow per row
      └─ DividerBlockView            ← Divider()

Inline formatting (bold, italic, code, link) is handled inside InlineRenderer, which iterates AttributedString.runs and applies theme overrides on top of what Text(AttributedString) already renders natively.

Requirements

Swift 6.0+
iOS 18+ / macOS 15+ / tvOS 18+ / watchOS 11+ / visionOS 2+