Getting Started with WebAssembly

WebAssembly (Wasm) is a binary instruction format that allows code written in multiple languages to run on the web at near-native speed.

What is WebAssembly?

  • A compilation target for languages like C, C++, Rust
  • Runs in all major browsers
  • Provides predictable performance
  • Works alongside JavaScript

Why WebAssembly Matters

✓ Near-native performance
✓ Language flexibility
✓ Security sandbox
✓ Cross-platform support

Your First Wasm Module

Here’s a simple example using Rust:

#[no_mangle]
pub extern "C" fn add(a: i32, b: i32) -> i32 {
    a + b
}

Compile to Wasm and call it from JavaScript:

const wasmModule = await WebAssembly.instantiateStreaming(
  fetch('module.wasm')
);
const result = wasmModule.instance.exports.add(2, 3);
console.log(result); // 5

Use Cases

  • Image/Video editing in the browser
  • Games with high performance needs
  • Scientific simulations
  • Cryptography operations
  • CAD applications

The Future

WebAssembly is opening new possibilities for web applications that were previously impossible to run in browsers efficiently.