Express.js - how to check express version?

You can use:

npm view express version

or:

npm info express version

Example output:

4.17.1

In your project go to the package.json file and search for "dependencies:" -> "express:"

Example

package.json file:

{
  "name": "example",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "dependencies": {
    "express": "^4.17.1",
    "mysql": "^2.18.1"
  }
}

You look for:

"dependencies": {
  "express": "^4.17.1"
}