This is unpublished documentation of working with Rust and WebAssembly, the published documentation is available on the main Rust and WebAssembly documentation site . Features documented here may not be available in released versions of tooling for Rust and WebAssembly.

Crates You Should Know

This is a curated list of awesome crates you should know about for doing Rust and WebAssembly development.

You can also browse all the crates published to crates.io in the WebAssembly category.

Interacting with JavaScript and the DOM

wasm-bindgen | crates.io | repository

wasm-bindgen facilitates high-level interactions between Rust and JavaScript. It allows one to import JavaScript things into Rust and export Rust things to JavaScript.

wasm-bindgen-futures | crates.io | repository

wasm-bindgen-futures is a bridge connecting JavaSript Promises and Rust Futures. It can convert in both directions and is useful when working with asynchronous tasks in Rust, and allows interacting with DOM events and I/O operations.

js-sys | crates.io | repository

Raw wasm-bindgen imports for all the JavaScript global types and methods, such as Object, Function, eval, etc. These APIs are portable across all standard ECMAScript environments, not just the Web, such as Node.js.

web-sys | crates.io | repository

Raw wasm-bindgen imports for all the Web's APIs, such as DOM manipulation, setTimeout, Web GL, Web Audio, etc.

Error Reporting and Logging

console_error_panic_hook | crates.io | repository

This crate lets you debug panics on wasm32-unknown-unknown by providing a panic hook that forwards panic messages to console.error.

console_log | crates.io | repository

This crate provides a backend for the log crate that routes logged messages to the devtools console.

Dynamic Allocation

wee_alloc | crates.io | repository

The Wasm-Enabled, Elfin Allocator. A small (~1K uncompressed .wasm) allocator implementation for when code size is a greater concern than allocation performance.

Parsing and Generating .wasm Binaries

parity-wasm | crates.io | repository

Low-level WebAssembly format library for serializing, deserializing, and building .wasm binaries. Good support for well-known custom sections, such as the "names" section and "reloc.WHATEVER" sections.

wasmparser | crates.io | repository

A simple, event-driven library for parsing WebAssembly binary files. Provides the byte offsets of each parsed thing, which is necessary when interpreting relocs, for example.

Interpreting and Compiling WebAssembly

wasmi | crates.io | repository

An embeddable WebAssembly interpreter from Parity.

cranelift-wasm | crates.io | repository

Compile WebAssembly to the native host's machine code. Part of the Cranelift (né Cretonne) code generator project.