WebAssembly Binary
WebAssembly (Wasm) is a binary instruction format for a stack-based virtual machine. It enables near-native performance in web browsers for applications like games, video editing, CAD, and scientific simulations. Code from C, C++, Rust, and Go compiles to Wasm for portable execution.
MIME Type
application/wasm
Type
Binary
Compression
Lossless
Advantages
- + Near-native execution speed in web browsers
- + Compile from C, C++, Rust, Go, and more
- + Sandboxed execution for security
- + Portable — runs in browsers and server-side via WASI
Disadvantages
- − No direct DOM access — requires JavaScript interop
- − Debugging is harder than JavaScript
- − Binary format is not human-readable
When to Use .WASM
Use Wasm for CPU-intensive web applications, porting native code to browsers, and serverless edge functions via WASI.
Technical Details
Wasm uses a compact binary format with typed functions, linear memory, and a validation step that ensures safety. It runs in a sandboxed environment with no direct access to the DOM — JavaScript bridges provide I/O. WASI extends Wasm for server-side use.
History
The W3C released WebAssembly 1.0 in 2017, developed by Mozilla, Google, Microsoft, and Apple. It was designed as a compilation target for the web, complementing JavaScript with deterministic, predictable performance.