Definition
WebAssembly (Wasm) is a portable binary instruction format enabling high-performance code execution in browsers and serverless environments. Swift 6.4 targets Wasm via JavaScriptKit bridging for cross-platform deployment beyond Apple ecosystems.
Key Points
- Swift 6.4: JavaScriptKit bridging up to 40× faster via safe bridging optimizations (2026-09-15-swift-6-4-released)
- Wasm SDK available from Swift.org Install page — no extra setup beyond SDK add
- Foundation FileManager improvements on WASI
40× figure is Apple/Swift team benchmark; cite as stated performance claim.