Fastify React: The 7x Faster Framework That Could Replace Next.js

For React developers frustrated with Next.js becoming increasingly complex and performance issues with each release, Fastify React emerges as a compelling alternative that offers significantly better performance. Recent benchmarks show Fastify React handling up to seven times more requests per second than Next.js in comparable scenarios, making it worth serious consideration for developers who prioritize speed and server-side control.

Fastify - A high-performance Node.js web framework designed for speed with over 33,000 GitHub stars, emphasizing its low overhead architecture that enables superior request handling

Understanding Fastify React: The High-Performance Alternative

Fastify React combines two powerful technologies: Fastify, a Node.js microframework similar to Express but with significantly lower overhead, and React for UI components. Unlike Next.js, which has evolved into a comprehensive framework with numerous built-in features, Fastify React focuses specifically on server-side rendering (SSR) and client-side hydration, giving developers more direct control over their server implementation.

The core advantage of Fastify React lies in its streamlined architecture. It works through Vite, allowing developers to write React components that can be rendered on the server using Fastify's high-performance engine. This approach deliberately avoids some of the complexity that has been added to Next.js over time, resulting in a leaner, faster framework that excels at its primary function.

Notably, the Fastify React team explored implementing React Server Components but ultimately decided against it due to documentation limitations and compatibility issues between Webpack and Vite's ESM imports. This decision reflects their focus on performance and reliability over adopting every new React feature.

Benchmark Results: Fastify React vs Next.js

To understand the performance difference between these frameworks, let's examine benchmark results from multiple tests. These benchmarks measure requests per second (RPS), a key indicator of how many users a server can simultaneously handle.

The SSR Performance Showdown repository comparing server-side rendering performance across multiple frameworks including Fastify React, Next.js, Vue, and other popular options

Basic Rendering Test

In a controlled test rendering a spiral visualization component:

Fastify React: 347 requests per second
Next.js: 49 requests per second
Performance ratio: Fastify React processes approximately 7x more requests

Local testing on an M1 MacBook Pro with 16GB RAM showed similar results, with Fastify React handling 3,000 requests in 10 seconds (271.2 RPS) compared to Next.js managing only 520 requests in the same timeframe (51 RPS).

Real-World Application Test

For a more practical comparison, a to-do list application was built with both frameworks, incorporating React hooks like useContext and server actions:

Next.js (hosted on Vercel, warm start): 5,000 requests in 10 seconds (467 RPS)
Fastify React (hosted on Digital Ocean): 5,000 requests in 10 seconds (487.8 RPS)
Next.js (cold start): Approximately 4,000 requests in 10 seconds

These results demonstrate that while the performance gap narrows in optimized production environments, Fastify React still maintains an edge. The difference becomes more pronounced when considering cold starts, which are common in serverless environments.

Setting Up a Fastify React Project

A basic Fastify React project consists of several key components working together to enable server-side rendering with React. Here's what the implementation looks like:

A Fastify server file that configures and runs the server on a specified port (typically 3000)
Vite configuration that sets up the Vite React and Vite Fastify React plugins
HTML template that includes mounting points for JavaScript hydration
React components that will be server-rendered and then hydrated on the client

JAVASCRIPT

// Example server.js for Fastify React
import Fastify from 'fastify'
import fastifyVite from '@fastify/vite'

const server = Fastify()

await server.register(fastifyVite, {
  root: import.meta.url,
  dev: process.env.NODE_ENV !== 'production',
  renderer: './renderer.js'
})

server.get('/', (req, reply) => {
  return reply.html()
})

await server.vite.ready()
await server.listen({ port: 3000 })

This setup enables Fastify to render React components on the server and send fully rendered HTML to the client, which is then hydrated with JavaScript for interactivity. The approach provides excellent performance while maintaining the developer experience React developers expect.

Deployment Considerations

Vercel deployment dashboard showing a Next.js todo application - while Vercel optimizes Next.js performance, Fastify React requires alternative hosting solutions for maximum performance benefits

One important consideration when choosing between these frameworks is deployment. Next.js has deep integration with Vercel, which provides optimized hosting specifically for Next.js applications. Deploying Fastify React on Vercel is possible but not as straightforward, requiring additional configuration.

For maximum performance with Fastify React, traditional hosting options like Digital Ocean, AWS, or other VPS providers often yield better results than serverless platforms. This is because Fastify can take full advantage of persistent server instances rather than dealing with cold starts in serverless environments.

When to Choose Fastify React Over Next.js

Fastify React is particularly well-suited for certain use cases and development teams:

Applications where server performance and request throughput are critical metrics
Teams that prefer more direct control over their server implementation
Projects that need SSR but don't require all the additional features of Next.js
Developers comfortable with Node.js server configuration and deployment
Applications hosted on traditional VPS or dedicated servers rather than serverless platforms
Teams frustrated with Next.js complexity or performance issues

Conclusion: Is Fastify React the Next.js Alternative You've Been Waiting For?

The performance advantages of Fastify React are clear, particularly in scenarios where raw request handling capability matters. While Next.js remains a more comprehensive framework with broader feature support and easier deployment options through Vercel, Fastify React offers a compelling alternative for developers who prioritize performance and simplicity.

For teams experiencing frustration with Next.js becoming increasingly complex or encountering performance bottlenecks, Fastify React represents a viable path forward that maintains the React development experience while significantly improving server-side performance. As web applications continue to demand better performance with lower resource usage, frameworks like Fastify React that focus on core functionality and speed will likely gain increased adoption.

Whether Fastify React becomes a mainstream alternative to Next.js will depend on community adoption and continued development, but its impressive performance metrics make it worth consideration for any React project where server-side rendering performance is a priority.

Fastify React: The 7x Faster Framework That Could Replace Next.js for Performance-Focused Developers