Fulmine.jsThe drop-in Express 5 replacement

Same API, same middleware, same tests. Built on uWebSockets.js instead of node:http, up to 20x faster where the framework does the work.

Migrate in one line

Why Fulmine

GitHub

⚡

Faster than Express, measured

1.3x to 4.9x on plain routing, 7x to 20x on a large route table, on every CI run. Routes are matched in C++ and a simple enough handler never enters JavaScript.

The numbers and where they come from

🔁

Zero rewrite

helmet, cors, passport, morgan, multer, express-session keep working. Every test runs against real Express first and the output must match byte for byte. Express 5's own suite passes, 1130 of 1130.

What is tested

🧩

Your framework works too

NestJS, Next.js, Astro, SvelteKit, React Router, Angular SSR, Apollo, tRPC, tsoa, MCP. Each one served twice in CI, on Express and on Fulmine, and compared.

Tested frameworks

🛠️

More than Express, when you want it

One process per core on one port, native WebSockets, built-in compression, pre-compressed static files, Server-Timing, PROXY protocol, TLS. All optional.

WebSockets

🧭

Nothing to guess

npx fulmine.js verify says whether this machine and your Docker image can run it. profile prints what listen() decided about each route. explain tells the story of one request.

profile and explain

📈

Ranked in public

HttpArena and web-frameworks run it on their hardware with their rules. No figure is copied here, the boards are the current ones.

Public benchmarks

One line

const express = require("fulmine.js"); // instead of require("express")

npx fulmine.js create my-app        # a new project, with a Dockerfile that works
npx fulmine.js migrate              # an existing one: rewrite the imports, list what to check