WebAssembly

Definition

Binary instruction format that allows code written in multiple languages to run at near-native speed in web browsers and on servers.

Use Cases

Frequently Asked Questions

What's the difference between WebAssembly and JavaScript?
JavaScript is a high-level scripting language commonly used to build interactive web pages. WebAssembly, or Wasm, is a low-level binary format designed for speed and portability. In practice, they often work together: JavaScript handles UI and browser interactions, while WebAssembly runs performance-heavy code such as graphics, simulations, audio processing, or compiled libraries.
When should I use WebAssembly?
Use WebAssembly when you need better performance than typical JavaScript can provide, when you want to reuse code written in languages like Rust, C, or C++, or when you need portable execution across browsers, edge environments, and servers. It is especially useful for games, media processing, CAD tools, scientific computing, cryptography, and sandboxed plugins. For standard website logic or simple business apps, JavaScript or a typical backend service is usually easier.
How much does WebAssembly cost?
WebAssembly itself is an open standard and does not have a license fee. Costs come from the environment where you run it, such as browser delivery, CDN bandwidth, cloud compute, serverless invocations, edge execution, storage, observability, and developer time. If you run Wasm on a cloud platform, pricing depends on that platform's CPU, memory, request volume, and network usage rather than on WebAssembly itself.

Category: emerging

Difficulty: advanced

See Also