Rust and WebAssembly quick start guide 2025

As of December 2025, Rust and WebAssembly is reorganizing. Documentation is currently out of date and not working. This is my notes on getting started using Rust WebAssembly. Most of the documentation still works - below is distilled version.

Install Rust toolchain

$ curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh

Below shows my Rust toolchain versions

q@x1m9:~/tmp$ cargo --version
cargo 1.92.0 (344c4567c 2025-10-21)
q@x1m9:~/tmp$ rustc --version
rustc 1.92.0 (ded5c06cf 2025-12-08)

Install wasm-pack - your one-stop shop for building, testing, and publishing Rust-generated WebAssembly.

$ sudo apt install build-essential
$ cargo install wasm-pack

wasm-pack version

q@x1m9:~/tmp$ wasm-pack --version
wasm-pack 0.13.1

Install cargo-generate - helps you get up and running quickly with a new Rust project by leveraging a pre-existing git repository as a template.

$ sudo apt install libssl-dev
$ sudo apt install pkg-config
$ cargo install cargo-generate

cargo-generate version

q@x1m9:~/tmp$ cargo-generate --version
cargo generate 0.23.7

Install npm

Install node version manager - nvm

$ curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.40.3/install.sh | bash

nvm version

q@x1m9:~/tmp$ nvm --version
0.40.3

Now install latest version of node

$ nvm install node

node version

q@x1m9:~/tmp$ node --version
v25.2.1

Clone project template

$ cargo generate --git https://github.com/rustwasm/wasm-pack-template.git --name wasm-game-of-life
$ cd wasm-game-of-life

Build the project

$ wasm-pack build

Putting it into a webpage, run in project root

$ sudo apt install git
$ npm init wasm-app www

Install dependencies

$ cd ~/p/wasm-game-of-life/www
$ npm install

Edit ~/p/wasm-game-of-life/www/package.json

$ nvim ~/p/wasm-game-of-life/www/package.json 

Add wasm-game-of-life to dependencies section of package.json and also note that devDependencies is updated.

{
  "name": "create-wasm-app",
  "version": "0.1.0",
  "description": "create an app to consume rust-generated wasm packages",
  "main": "index.js",
  "bin": {
    "create-wasm-app": ".bin/create-wasm-app.js"
  },
  "scripts": {
    "build": "webpack --config webpack.config.js",
    "start": "webpack-dev-server"
  },
  "repository": {
    "type": "git",
    "url": "git+https://github.com/rustwasm/create-wasm-app.git"
  },
  "keywords": [
    "webassembly",
    "wasm",
    "rust",
    "webpack"
  ],
  "author": "Ashley Williams ",
  "license": "(MIT OR Apache-2.0)",
  "bugs": {
    "url": "https://github.com/rustwasm/create-wasm-app/issues"
  },
  "homepage": "https://github.com/rustwasm/create-wasm-app#readme",
  "devDependencies": {
    "webpack": "^5.0.0",
    "webpack-cli": "^5.0.0",
    "webpack-dev-server": "^4.0.0",
    "copy-webpack-plugin": "^11.0.0",
    "hello-wasm-pack": "^0.1.0"
  },
  "dependencies": {
    "wasm-game-of-life": "file:../pkg"
  }
}

Edit ~/p/wasm-game-of-life/www/index.js

$ nvim ~/p/wasm-game-of-life/www/index.js

Add wasm-game-of-life package to index.js

import * as wasm from "wasm-game-of-life";

wasm.greet();

Install wasm-game-of-life package and force clean as we have upgraded devDependencies

$ cd ~/p/wasm-game-of-life/www
$ rm -rf node_modules package-lock.json
$ npm install

Fix ~/p/wasm-game-of-life/www/webpack.config.js

$ nvim ~/p/wasm-game-of-life/www/webpack.config.js

Observe we have changed CopyWebpackPlugin and added asyncWebAssembly

const CopyWebpackPlugin = require("copy-webpack-plugin");
const path = require('path');

module.exports = {
  entry: "./bootstrap.js",
  output: {
    path: path.resolve(__dirname, "dist"),
    filename: "bootstrap.js",
  },
  mode: "development",
  plugins: [
    new CopyWebpackPlugin({
      patterns: [
        { from: "index.html" },
      ],
    })
  ],
  experiments: {
    asyncWebAssembly: true,
  },
};

Now run it

$ npm run start

Open http://localhost:8080