Fastify 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
A fast, low-overhead web framework for building servers and APIs with Node.js.
Open source · MIT
A tiny library for building small async HTTP services in Node.js.
The short answer
Choose Fastify if you need…
- Node.js developers building JSON APIs or backend services
- Teams that care about request throughput and want a lightweight framework
- Projects that want schema-based validation of routes and responses
- Developers who want to organize code into reusable plugins
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
| Fastify | micro | |
|---|---|---|
| Type | Library | Library |
| Price | Free and open source | Free and open source |
| Licence | MIT | MIT |
| GitHub stars | 37.3k | 10.6k |
| Setup difficulty | Beginner | 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
Fastify
Fastify is a framework for building web servers and APIs in Node.js. You define routes, such as a URL that returns data, and Fastify handles incoming requests with minimal extra work per request. It also offers a plugin system, input and output validation using JSON Schema, and built-in logging through Pino.
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
Fastify
- Node.js developers building JSON APIs or backend services
- Teams that care about request throughput and want a lightweight framework
- Projects that want schema-based validation of routes and responses
- Developers who want to organize code into reusable plugins
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
Fastify
- The README reports high request throughput in a synthetic hello-world benchmark, with the caveat that real results depend on the application
- Supports JSON Schema validation and serialization for routes
- Includes a plugin architecture and hooks for extending behavior
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
Fastify
- Beginners who have not yet learned Node.js basics, since the framework assumes JavaScript familiarity
- Projects that need a non-Node.js language, because Fastify is for Node.js only
- Teams expecting a large built-in feature set; much functionality comes from plugins, per the docs
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
Fastify
- Benchmark figures come from the maintainers' own synthetic test and may not match your workload
- The README's benchmark table lists an older Fastify version (4.0.0), so the numbers are not current
- Binding to 0.0.0.0 in containers requires care, since the README warns of security risks
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
Fastify
Install Fastify in an existing project
npm i fastifyGenerate a new Fastify project
npm init fastifymicro
Clone the repository
git clone https://github.com/vercel/microFrequently asked questions
What is the difference between Fastify and micro?
Fastify: A fast, low-overhead web framework for building servers and APIs with Node.js. micro: A tiny library for building small async HTTP services in Node.js. Fastify suits node.js developers building json apis or backend services, while micro suits developers who want a minimal http service in node.js.
Are Fastify and micro free?
Fastify: Free and open source. micro: Free and open source.
Which is easier to set up, Fastify or micro?
Fastify is easier to get started with (rated beginner); micro is rated intermediate and usually needs more setup.
Is Fastify or micro more popular?
Fastify has more GitHub stars (37.3k) than micro (10.6k). Popularity isn't the same as fit — check which one matches your use case above.
What are other alternatives to Fastify and micro?
Other options people compare them with include Express, Koa, Hono.
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.