Use Express for a Node.js server

Cost

Open source. MIT licence, free to run on your own servers.

How to do it

Express 1.0 came out in December 2010, and version 5.3.0 shipped in October 2026. The Express support page lists 5.x as supported since September 2024. It is the most used Node server framework in the 2026 Stack Overflow survey, at 15.6%, with about 87 million weekly downloads. It is MIT licensed and run under the OpenJS Foundation. Express 5 passes errors from async handlers to the error handler by itself. Choose something else when throughput is the main limit. Fastify passes the tests, with 1.0 in March 2018, 5.12.7 in October 2026 and 9 million weekly downloads. Choose NestJS when a large team wants a fixed module structure, and stay on 11 until 12 is six months old. Check every request body, as Use Zod or Pydantic to check every input says.

Examples

Using these examples: they show one way to follow this rule. Keep the behaviour and the check, not the syntax. Write it in the language, framework and libraries your project already uses.

JavaScript example

import express from 'express';

const app = express();
app.use(express.json({ limit: '100kb' }));
app.get('/orders/:id', async (req, res) => res.json(await findOrder(req.params.id)));
app.listen(3000);

Python example

import json

def express_major(package_json: str) -> int:
    version = json.load(open(package_json))["dependencies"]["express"]
    return int(version.lstrip("^~").split(".")[0])

assert express_major("package.json") >= 5

How to check

package.json lists express at major version 5 or higher, and no route file wraps async handlers in a try and catch only to call next.

Sources

• Express
• Express version support

Related rules

• Use Zod or Pydantic to check every input in Software choices