Koa
Koa is a HTTP middleware-based framework designed to develop Node.js applications and API. With a small code base of about 570 lines, the project offers basic HTTP functions, such as content negotiation and routing, but does not come with any ready-made middleware. The Middleware structure allows requests to be processed in the down direction and responses to be filtered and manipulated in the up direction.
Koa
100koajs · Web Frameworks & Runtimes
- You can create flexible middleware chains using async functions.
- You can manage incoming HTTP requests and responses via the Context object.
- You can perform basic operations such as content negotiation and HTTP routing with a minimal code structure.
- • NeutralHacker News
Koa – Next-generation web framework for Node.js
“Express is still maintained, by a bunch of us, but personally I'll be focusing mostly on Koa. They're separate because conceptually Koa is quite different, the migration from the would-be Express 3.0 -> 4.0 would mean rewriting the app”
- • NeutralHacker News
Koa – Next-generation web framework for Node.js
“Koa is only usable with >= 11.9 behind the --harmony flag, I doubt they'd want to release a new version of Express that most people can't/won't even use.”
Verified against README · Oct 26, 2026 · source