Express vs Fastify
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 minimal, unopinionated web framework for building servers and APIs with Node.js.
Open source · MIT
A fast, low-overhead web framework for building servers and APIs with Node.js.
The short answer
Choose Express if you need…
- Developers building JavaScript or Node.js back-end servers
- Teams building REST-style APIs in Node.js
- People who want a small framework and prefer choosing their own libraries
- Learners who want to understand how web servers handle requests
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
Side-by-side
| Express | Fastify | |
|---|---|---|
| Type | Framework | Library |
| Price | Free and open source | Free and open source |
| Licence | MIT | MIT |
| GitHub stars | 69.6k | 37.3k |
| Setup difficulty | Intermediate | Beginner |
| How you get it | Install with a package manager | Install with a package manager |
| Main language | JavaScript | JavaScript |
| Last code update | 4 days ago | 4 days ago |
What each one is
Express
Express is a small web framework for Node.js, the JavaScript runtime that runs outside the browser. It helps you handle web requests, define routes, and send responses without writing all the low-level server code yourself. It is described as unopinionated and minimalist, so it leaves most structural choices to the developer.
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.
Best for
Express
- Developers building JavaScript or Node.js back-end servers
- Teams building REST-style APIs in Node.js
- People who want a small framework and prefer choosing their own libraries
- Learners who want to understand how web servers handle requests
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
Strengths
Express
- Minimal core that is easy to learn and extend
- Unopinionated, so it fits many project structures
- Widely used, with 69,580 GitHub stars and an MIT license
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
Not ideal for
Express
- People who want a full, batteries-included framework with conventions decided for them, since Express leaves most structure to you
- Non-programmers, because it requires writing JavaScript code
- Projects that do not use Node.js
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
Trade-offs
Express
- Leaves structure, validation, and many features to third-party packages, which means more decisions for you
- Requires familiarity with Node.js and JavaScript
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
Getting started
Fastify
Install Fastify in an existing project
npm i fastifyGenerate a new Fastify project
npm init fastifyFrequently asked questions
What is the difference between Express and Fastify?
Express: A minimal, unopinionated web framework for building servers and APIs with Node.js. Fastify: A fast, low-overhead web framework for building servers and APIs with Node.js. Express suits developers building javascript or node.js back-end servers, while Fastify suits node.js developers building json apis or backend services.
Are Express and Fastify free?
Express: Free and open source. Fastify: Free and open source.
Which is easier to set up, Express or Fastify?
Fastify is easier to get started with (rated beginner); Express is rated intermediate and usually needs more setup.
Is Express or Fastify more popular?
Express has more GitHub stars (69.6k) than Fastify (37.3k). Popularity isn't the same as fit — check which one matches your use case above.
What are other alternatives to Express and Fastify?
Other options people compare them with include Koa.
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.