pdfkit

PDFKit (iOS)

Render, navigate, annotate, search, and fill PDFs. import PDFKit. iOS 11+; this skill targets the iOS 26 era. PDFKit is UIKit-based — there is no native SwiftUI PDFView, so wrap it with UIViewRepresentable (see swiftui-uikit-interop).

• Threading: PDFView and all UI live on the main thread. Loading a large PDFDocument, rendering thumbnails, and write(to:) are expensive — run them off the main actor and hand the finished object back to the view.
• Fintech note: never write account statements/receipts to a world-readable path. Export to an app-sandbox URL and, if it leaves the device or persists, encrypt at rest — see swift-security. PDFKit's own owner/user passwords (below) are AcroForm encryption, not a substitute for file-level protection.

Contents

• Display in SwiftUI
• PDFDocument — load, save, encrypt
• PDFPage — bounds, thumbnail, render
• Navigate, select, search
• Annotations
• Forms (AcroForm widgets)
• Thumbnails & outline
• PDFDocumentDelegate
• Correctness checklist
• References: references/annotations-forms.md, references/display-search.md

Display in SwiftUI

PDFView is a UIView. Bridge it once and drive it through the document.

import SwiftUI
import PDFKit

struct PDFKitView: UIViewRepresentable {
    let document: PDFDocument

    func makeUIView(context: Context) -> PDFView {
        let view = PDFView()
        view.autoScales = true                    // fit-to-width, tracks rotation/resize
        view.displayMode = .singlePageContinuous   // .singlePage | .twoUp | .twoUpContinuous
        view.displayDirection = .vertical          // or .horizontal
        view.usePageViewController(false)          // true = page-curl (iBooks-style)
        return view
    }

    func updateUIView(_ view: PDFView, context: Context) {
        if view.document !== document { view.document = document }
    }
}