Koa vs micro
Which should you use? A side-by-side look at what each one does, who it suits, what it costs, how hard it is to set up, and where each falls short.
Open source · MIT
Small Node.js web framework built on async functions for writing HTTP middleware.
Open source · MIT
A tiny library for building small async HTTP services in Node.js.
The short answer
Choose Koa if you need…
- 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
Choose micro if you need…
- Developers who want a minimal HTTP service in Node.js
- Teams building small single-purpose endpoints or microservices
- People already familiar with async/await in JavaScript or TypeScript
Side-by-side
| Koa | micro | |
|---|---|---|
| Type | Library | Library |
| Price | Free and open source | Free and open source |
| Licence | MIT | MIT |
| GitHub stars | 35.7k | 10.6k |
| Setup difficulty | Intermediate | Intermediate |
| How you get it | Install with a package manager | Install with a package manager |
| Main language | JavaScript | TypeScript |
| Last code update | 4 days ago | 6 months ago |
What each one is
Koa
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.
micro
Micro is a small Node.js library from Vercel for writing HTTP microservices using async and await. It focuses on handling requests and returning responses with very little setup. The README provided here is truncated, so details beyond that core purpose are not confirmed.
Best for
Koa
- 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
micro
- Developers who want a minimal HTTP service in Node.js
- Teams building small single-purpose endpoints or microservices
- People already familiar with async/await in JavaScript or TypeScript
Strengths
Koa
- 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
micro
- Small, focused scope centered on async HTTP handlers
- MIT licensed and open source
- Backed by the Vercel organization and has a large star count on GitHub
Not ideal for
Koa
- 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
micro
- Beginners looking for a full web framework with routing, templates, and many built-in features, since the README excerpt does not describe those
- Projects that need a long-running, feature-rich server with a large plugin ecosystem, since this excerpt does not show one
Trade-offs
Koa
- 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
micro
- The README excerpt is truncated, so setup and API details could not be verified here
- Its scope is narrow, so you may need other libraries for routing, middleware, or databases
- Latest release info shows no binaries, so use is through the code or package manager
Getting started
micro
Clone the repository
git clone https://github.com/vercel/microFrequently asked questions
What is the difference between Koa and micro?
Koa: Small Node.js web framework built on async functions for writing HTTP middleware. micro: A tiny library for building small async HTTP services in Node.js. Koa suits node.js developers who want a minimal web framework they can shape themselves, while micro suits developers who want a minimal http service in node.js.
Are Koa and micro free?
Koa: Free and open source. micro: Free and open source.
Is Koa or micro more popular?
Koa has more GitHub stars (35.7k) than micro (10.6k). Popularity isn't the same as fit — check which one matches your use case above.
What are other alternatives to Koa and micro?
Other options people compare them with include Express, Fastify, Hono, Apollo Server.
Keep comparing
Built from our catalogue entries for both products: open-source details come from each project's README (AI-assisted, refreshed weekly) and GitHub data; AI-tool details are editorial. Spotted something wrong? Let us know from either product's page.