Develop advanced web content

Description: Develop in JavaScript, WebGL, or WebAssembly? Learn how the latest updates to Safari and WebKit — including language changes to class syntax — can help simplify your development process, enhance performance, and improve security. We’ll explore several web APIs that can help provide better interoperability and bring new capabilities to your web content.

JavaScript enhancements

  • Class field syntax
    • Private instance fields and methods
      • use #variableName instead of _variableName
      • define methods with #methodName instead of methodName
      • applies to static fields
  • Language-enforced access protection
    • Public and private static fields
  • Weak references
    • Weakly refer to an object without preventing garbage collection: use new WeakRef(object) to held a weak reference to an object
    • Get underlying object from weak reference if it exists: check via deref()? e.g. weakObject.deref()?.objectMethod();
    • Register notifications about objects garbage collection via FinalizationRegistry (warning: you may not get the callback from FinalizationRegistry right way because it runs on event loop)
  • Top-level await
    • available in modules
    • use await outside of a async function at the top level
    • async modules block execution of modules importing them
  • Module in workers
    • efficient resource utilization
    • ergonomic and performance benefits of modules (dynamic import, optimized loading and execution, and dependency management)
    • easy to move heavy work to background thread
    • modules are now available in different types of workers, including web worker, service worker, and worklet
  • Internationalization improvements

WebAssembly updates

What's WebAssembly?

  • binary instruction format for a stack-based virtual machine
  • type of a code that can be run in modern web browsers with performance close to native code
  • designed to be a portable compilation target for programming languages like C, C++, or Rust


  • bulk memory operations
  • non-trapping float-int conversions
  • Sign-extension operators
  • JavaScript BigInt integration
  • reference types
  • streaming download and compilation

New web APIs

New features/feature updates:

  • WebGL 2.0
  • Storage Access
  • WebM
  • VP9
  • Media Recorder
  • Audio Worklet
  • Web Share
  • Media Session
  • Speech recognition

Missing anything? Corrections? Contributions are welcome 😃


Written by

Federico Zanetello

Federico Zanetello

Software engineer with a strong passion for well-written code, thought-out composable architectures, automation, tests, and more.