WWDC 2021 Viewing Guide

Here’s my viewing guide for the WWDC 2021 sessions I found interesting this year.

Where Do I Start?

Watch the Platforms State of the Union (SOTU) for a summary of what’s new. It has a demo of Xcode Cloud, Holly Borla introducing the Swift concurrency changes, Josh Shaffer covering updates to SwiftUI and more.

You don’t have to learn everything new today!

There’s a huge amount of new stuff to learn. You may feel like you’re getting left behind. Don’t let it overwhelm you. You’ve got time.

Many of the new API’s require iOS 15 so it may be a while before you can use them. Don’t burn yourself out trying to keep up.

Watching The Sessions

I watch the videos using the Apple Developer app. It’s available on macOS and iOS. The video player supports from 0.5x to 2x playback, many videos have transcripts and support copying of the onscreen sample code.

There are a lot of sessions, but many are short (10-20 minutes). There’s no padding and Apple’s engineers get to the point quickly.


The open source nature of the Swift project makes these sessions less of a surprise but they are still essential viewing:

  • What’s new in Swift A recap of what’s been happening with Swift and some of the changes in Swift 5.5.

Swift Concurrency

Swift Concurrency and async/await/actors are one of the big features this year. This first session is essential viewing but note that Swift Concurrency needs iOS 15:

  • Meet async/await in Swift I was a little unsure about the excitement around async/await. This session helped me understand what it means.

Deeper sessions that I’m going to be rewatching many times…

The theory is great but how do you use it?

Other interesting Swift sessions


The third release of SwiftUI is a solid update with lots of rough edges removed and gaps filled:

  • What’s new in SwiftUI An overview of many of the changes. Async image loading, async task modifiers, list separator customizations, swipe actions, tables on macOS, searching, canvas for drawing, markdown text support, focus and button styles and more. Essential viewing.

The detailed sessions:


Don’t forget about UIKit. There are some useful refinements here too:

The detailed sessions:


A big focus on the keyboard this year:

Mac & Catalyst

  • What’s new in AppKit AppKit also gets SF Symbols 3, TextKit 2, and Swift Concurrency API updates. New property wrapper for view invalidation removes some boilerplate.
  • Meet Shortcuts for macOS Shortcuts come to the mac. Includes migration tool for (now legacy) Automator workflows.

The many ways to make iOS apps run on a Mac:

Two-part code-along building a Mac app. Using SwiftUI makes this familiar ground for iOS developers:


Always-on display for apps is the big feature this year:

Developer Tools

The big news is Xcode Cloud, but there’s also a new documentation compiler and plenty of improvements in Xcode 13.

Xcode Cloud

DocC - Documentation Compiler

This is a huge improvement to the Xcode documentation tooling.

Interface Builder

  • Build interfaces with style Finally… you can reorder storyboard scenes in the outline view and edit properties on groups of constraints. New button and table view cell content styles, SF Symbol and Accessibility inspector support.


  • Localize your SwiftUI app Keyboard shortcuts get translated to work on different keyboards. Opt-in existing projects to use the compiler to extract strings.
  • Streamline your localized strings Xcode 13 can directly view and edit exported localization catalogs. Automatic grammar agreement (for English and Spanish).

Source Control


Performance and Debugging

System Frameworks


  • What’s new in Foundation A completely new Swift AttributedString that supports inline markdown styles. Formatters get a rewrite removing the need to create the formatter. Grammar agreement in localized strings (Spanish and English only).



Core Data



Other Services


The accessibility sessions are always good:

App Store and Distribution

App Store


Photos and Camera

Privacy and Security

Safari and Web

App Services

Widgets were the surprise hit of last year, but I’m not sure I’ve seen an App Clip in the wild.


App Clips


Other Services


SF Symbols

Audio and Video

SharePlay and ShazamKit are the big news this year:



MusicKit and Apple Music

Other Audio Sessions

Augmented Reality

Still no Apple Glasses but ARKit and RealityKit keep growing. Object Capture is the big development this year:

Machine Learning and Vision

And Finally…