In this lesson you will learn with webpack in single-spa, why it matters within build configuration, and how to use it correctly with clear, copy-ready examples.
with Webpack Overview
with Webpack lets you structure single-spa work so it stays readable, testable, and easy to scale. Instead of ad-hoc code, you follow a clear pattern that other developers can recognise immediately.
The key is to keep with webpack focused and predictable. Start from the minimal example here, then layer in only the complexity your feature actually needs.
Start from a minimal with Webpack example and grow it only as needed.
Keep configuration explicit so with Webpack behaves the same in every environment.
Name things clearly so teammates understand your with Webpack at a glance.
Add tests around with Webpack early to lock in expected behaviour.
Single-SPA Cheatsheet
Core single-spa APIs related to with webpack.
API
Example
Purpose
registerApplication
registerApplication({ name, app, activeWhen })
Register a micro frontend
activeWhen
activeWhen: ['/checkout']
Route ownership
start
start()
Begin routing
bootstrap
export async function bootstrap()
One-time setup
mount
export async function mount(props)
Render the app
unmount
export async function unmount(props)
Clean up the app
import map
systemjs-importmap
Locate app bundles
How with Webpack Works in Single-SPA
with Webpack is part of how single-spa lets multiple applications — even in different frameworks — coexist on one page. A root config registers each app and controls when it is active.
single-spa orchestrates multiple framework apps on one page through a root config.
A root config registers apps and calls start().
Each app exports bootstrap, mount, and unmount lifecycles.
activeWhen decides which routes each app owns.
Import maps resolve each app's bundle at runtime.
Practical Guidance for with Webpack
For reliable micro frontends, with webpack should isolate failures and keep shared state minimal. Let each team own its app end to end while agreeing on a few shared contracts.
Concern
Recommendation
Isolation
One app's crash should not break others
Shared state
Prefer shared utility modules over globals
Routing
Keep activeWhen rules explicit and non-overlapping
Deployment
Release via import-map updates per app
Common Mistakes
Copying with webpack snippets without understanding what each line does.
Skipping error handling and edge cases when wiring up with webpack.
Leaving with webpack untested, so regressions slip into production.
Over-engineering with webpack before you actually need the extra flexibility.
Key Takeaways
with Webpack is a core part of working effectively with single-spa.
Start small and keep with webpack focused on a single responsibility.
Apply consistent patterns so with webpack scales across your project.
Test and document with webpack to keep it maintainable over time.
Pro Tip
When you get stuck on with webpack, reduce it to the smallest reproducible example first — most single-spa issues become obvious once the noise is gone.
You now understand with webpack in single-spa and how to apply it in real projects. Next, continue with with Vite to keep building your skills.