Koa
Small Node.js web framework built on async functions for writing HTTP middleware.
- Stars
- 35.7k
- Forks
- 3.2k
- Licence
- MIT
- Language
- JavaScript
- Last update
- 4 days ago
- Type
- Library
What it is
Koa is a web framework for Node.js that lets developers build HTTP servers and APIs by chaining middleware functions. It uses modern async/await syntax, so each step can pause, wait for work like a database call, and then pass control onward. Developers use it as a lightweight base they can extend with their own choice of add-ons.
- Build a JSON API that wraps database or external service calls in async middleware
- Add logging, error handling, or authentication as reusable middleware layers
- Serve a basic web application or static responses from a small Node.js server
Great for
- Node.js developers who want a minimal web framework they can shape themselves
- Teams building APIs or web servers who prefer async/await middleware
- Developers familiar with Express-style middleware who want a smaller core
Not ideal for
- Complete beginners new to Node.js, since Koa ships with little built in and assumes familiarity with HTTP and middleware
- Projects that need a full batteries-included framework out of the box, because routing, body parsing and similar features come from separate packages
How to get it
- 1
Install with a package manager
You'll need: Node.js
Install Koa from npm
npm install koa - 2
Run it
- Install Node.js on your machine
- Run npm install koa in your project folder
- Create an app file that imports Koa and registers a middleware function
- Start the file with node and open the local address in a browser
- 3
Get the most out of it
- Combine Koa with separate router and body-parser packages to handle routes and request bodies
- Write small middleware functions and compose them so each handles one concern
- Use the official site at koajs.com for documentation and guides
Downloads
Strengths
- Uses ES2017 async functions, so control flow reads top to bottom without callback nesting
- Minimal core keeps the framework small and lets you choose extra pieces
- MIT licensed and widely used, with a large star count on GitHub
Trade-offs
- Little is included by default, so routing and parsing require additional packages
- Public README was truncated here, so detailed API and version-specific behavior could not be verified from this entry
How it compares
| Project | Stars | Type | Level | Updated | Best for |
|---|---|---|---|---|---|
| koa (this) | 35.7k | Library | intermediate | 4 days ago | Node.js developers who want a minimal web framework they can shape themselves |
| express | 69.6k | Framework | intermediate | 4 days ago | Developers building JavaScript or Node.js back-end servers |
| fastify | 37.3k | Library | beginner | 4 days ago | Node.js developers building JSON APIs or backend services |
| hono | 32.8k | Library | beginner | 5 days ago | Developers writing TypeScript or JavaScript HTTP APIs |
| apollo-server | 14k | Library | intermediate | 5 days ago | Node.js developers who want to add a GraphQL API to an existing Express, Koa or Hapi app |
| egg | 19k | Framework | intermediate | 14 days ago | Teams building larger Node.js backend applications that need structure |
Stats synced from GitHub. The assessment above was drafted with AI from the project's README on 2026-10-29 and may miss recent changes — check the README before relying on a command. MIT licence: free to use, modify and distribute, including commercially, as long as you keep the copyright notice.