wasm-pack

TLDR

Build Rust project for WebAssembly

$ wasm-pack build

Build for npm publishing

$ wasm-pack build --target bundler

Build for web browser

$ wasm-pack build --target web

Build for Node.js

$ wasm-pack build --target nodejs

Build with custom output directory

$ wasm-pack build --out-dir [dist]

Build in development mode

$ wasm-pack build --dev

Publish to npm

$ wasm-pack publish

Create new project from template

$ wasm-pack new [project-name]

SYNOPSIS

wasm-pack [options] command [args]

wasm-pack is a build tool for Rust-generated WebAssembly. It compiles Rust code to WebAssembly, generates JavaScript bindings using wasm-bindgen, and produces npm-ready packages.
The build process compiles Rust to the wasm32-unknown-unknown target, runs wasm-bindgen to generate JavaScript glue code, and optionally runs wasm-opt for optimization. The output includes .wasm files, TypeScript definitions, and package.json for npm.
Different targets generate different JavaScript module formats: bundler for webpack/rollup, web for ES modules in browsers, nodejs for CommonJS, and no-modules for script tags.
Install via cargo: `cargo install wasm-pack`

PARAMETERS

--target target

Output target: bundler (default), web, nodejs, deno, no-modules.

--out-dir dir

Output directory (default: pkg).

--out-name name

Output file basename.

--dev

Development build with debug info.

--profiling

Release build with debug info.

--release

Optimized release build (default).

--scope scope

npm scope for publishing.

--mode mode

Build mode: normal, no-install, force.

--verbose

Enable verbose output.

--quiet

Suppress output.

-h, --help

Display help.

-V, --version

Display version.

COMMANDS

build: Compile to WebAssembly and generate bindings.
new: Create new project from template.
pack: Create tarball for npm publishing.
publish: Publish package to npm registry.
login: Login to npm registry.
test: Run wasm-pack tests.

CAVEATS

Requires Rust toolchain with wasm32-unknown-unknown target. First build may download wasm-bindgen and wasm-opt. Some Rust crates may not compile to WebAssembly. WASI support requires different tooling.

HISTORY

wasm-pack was created by the Rust and WebAssembly Working Group to simplify publishing Rust-generated WebAssembly to npm. It streamlines the workflow of compiling, binding generation, and package publishing into a single tool.