---
id: wasm-pack
title: Using wasm-pack
---

This tool was created by the Rust / Wasm Working Group and is the most actively developed tool for building WebAssembly applications. It supports packaging code into `npm` modules and has an accompanying [Webpack plugin](https://github.com/wasm-tool/wasm-pack-plugin) for easy integration with an existing JavaScript application. More information is given in [the `wasm-pack` documentation](https://rustwasm.github.io/docs/wasm-pack/introduction.html).

:::note
Note that the crate-type in your `Cargo.toml` will need to be `cdylib` when using `wasm-pack`
:::

## Install

```bash
cargo install wasm-pack
```

## Build

This command will produce a bundle in the `./pkg` directory with your app's compiled WebAssembly 
along with a JavaScript wrapper which can be used to start your application.

```bash
wasm-pack build --target web
```

## Bundle

For more information on Rollup visit this [guide](https://rollupjs.org/guide/en/#quick-start)

```bash
rollup ./main.js --format iife --file ./pkg/bundle.js
```

## Serve

Feel free to use your preferred server. Here we use a simple Python server to serve the built app.

```bash
python -m http.server 8000
```

## Supported Targets

* `wasm32-unknown-unknown`