Note that rails 6 uses webpacker and so bootstrap integration is different from Rails 5. Bootstrap relies on a the popper.js library, so this tutorial shows how to install both. This tutorial assumes that you have configured Webpacker to compile both javascript and stylesheet assets. For instructions on doing this, please see the Webpacker tutorial.

Install node modules

Install bootstrap.

yarn add @popperjs/core bootstrap

Your package.json should now include both packages. Your versions will likely be different than the ones displayed below.

"dependencies": {
  "@popperjs/core": "^2.10.2",
  "bootstrap": "^5.1.3",

Configure webpacker

Add the following to app/frontend/packs/application.js.

import "bootstrap"

Add the following to app/frontend/stylesheets/application.scss.

@import '~bootstrap/scss/bootstrap';

Add the following to config/webpack/environment.js.

// config/webpack/environment.js

const { environment } = require('@rails/webpacker');
const webpack = require("webpack");

environment.plugins.append("Provide", new webpack.ProvidePlugin({
    Popper: ['popper.js', 'default']

module.exports = environment