Node.js Error: Cannot find module express

Question

I wrote my first node.js app, but it can't find express library:

C:\ChatServer\Server>node server.js

module.js:340
    throw err;
          ^
Error: Cannot find module 'express'
    at Function.Module._resolveFilename (module.js:338:15)
    at Function.Module._load (module.js:280:25)
    at Module.require (module.js:364:17)
    at require (module.js:380:17)
    at Object.<anonymous> (C:\ChatServer\Server\server.js:6:9)
    at Object.<anonymous> (C:\ChatServer\Server\server.js:25:4)
    at Module._compile (module.js:456:26)
    at Object.Module._extensions..js (module.js:474:10)
    at Module.load (module.js:356:32)
    at Function.Module._load (module.js:312:12)

But express is intalled (with -g key):

C:\ChatServer\Server>npm install -g express
npm http GET https://registry.npmjs.org/express
npm http 304 https://registry.npmjs.org/express
npm http GET https://registry.npmjs.org/connect/2.7.11
npm http GET https://registry.npmjs.org/commander/0.6.1
npm http GET https://registry.npmjs.org/range-parser/0.0.4
npm http GET https://registry.npmjs.org/mkdirp/0.3.4
npm http GET https://registry.npmjs.org/cookie/0.1.0
npm http GET https://registry.npmjs.org/buffer-crc32/0.2.1
npm http GET https://registry.npmjs.org/fresh/0.1.0
npm http GET https://registry.npmjs.org/methods/0.0.1
npm http GET https://registry.npmjs.org/send/0.1.0
npm http GET https://registry.npmjs.org/cookie-signature/1.0.1
npm http GET https://registry.npmjs.org/debug
npm http 304 https://registry.npmjs.org/mkdirp/0.3.4
npm http 304 https://registry.npmjs.org/range-parser/0.0.4
npm http 304 https://registry.npmjs.org/cookie/0.1.0
npm http 304 https://registry.npmjs.org/connect/2.7.11
npm http 304 https://registry.npmjs.org/commander/0.6.1
npm WARN package.json [email protected] No repository field.
npm http 304 https://registry.npmjs.org/buffer-crc32/0.2.1
npm http 304 https://registry.npmjs.org/fresh/0.1.0
npm http 304 https://registry.npmjs.org/methods/0.0.1
npm http 304 https://registry.npmjs.org/send/0.1.0
npm http 304 https://registry.npmjs.org/cookie-signature/1.0.1
npm WARN package.json [email protected] No repository field.
npm WARN package.json [email protected] No readme data.
npm WARN package.json [email protected] No repository field.
npm WARN package.json [email protected] No repository field.
npm WARN package.json [email protected] No repository field.
npm http 304 https://registry.npmjs.org/debug
npm http GET https://registry.npmjs.org/mime/1.2.6
npm http GET https://registry.npmjs.org/qs/0.6.5
npm http GET https://registry.npmjs.org/send/0.1.1
npm http GET https://registry.npmjs.org/formidable/1.0.14
npm http GET https://registry.npmjs.org/cookie/0.0.5
npm http GET https://registry.npmjs.org/bytes/0.2.0
npm http GET https://registry.npmjs.org/pause/0.0.1
npm http 304 https://registry.npmjs.org/mime/1.2.6
npm http 304 https://registry.npmjs.org/bytes/0.2.0
npm WARN package.json [email protected] No repository field.
npm http 304 https://registry.npmjs.org/pause/0.0.1
npm WARN package.json [email protected] No repository field.
npm http 304 https://registry.npmjs.org/formidable/1.0.14
npm http 304 https://registry.npmjs.org/qs/0.6.5
npm http 304 https://registry.npmjs.org/send/0.1.1
npm http 304 https://registry.npmjs.org/cookie/0.0.5
npm http GET https://registry.npmjs.org/mime
npm http 304 https://registry.npmjs.org/mime
C:\Users\Dmitry\AppData\Roaming\npm\express -> C:\Users\Dmitry\AppData\Roaming\npm\node_modules\express\bin\express
npm WARN package.json [email protected] 'repositories' (plural) Not supported.
npm WARN package.json Please pick one as the 'repository' field
npm WARN package.json [email protected] No repository field.
npm WARN package.json [email protected] No repository field.
[email protected] C:\Users\Dmitry\AppData\Roaming\npm\node_modules\express
├── [email protected]
├── [email protected]
├── [email protected]
├── [email protected]
├── [email protected]
├── [email protected]
├── [email protected]
├── [email protected]
├── [email protected]
├── [email protected] ([email protected])
└── [email protected] ([email protected], [email protected], [email protected], [email protected], [email protected], [email protected])

Some information:

C:\ChatServer\Server>npm --version
1.2.24

C:\ChatServer\Server>node --version
v0.10.9

C:\ChatServer\Server>npm --version
1.2.24

C:\ChatServer\Server>npm ls -g installed express
npm WARN package.json [email protected] No repository field.
npm WARN package.json [email protected] No repository field.
npm WARN package.json [email protected] No repository field.
npm WARN package.json [email protected] No repository field.
npm WARN package.json [email protected] No repository field.
npm WARN package.json [email protected] 'repositories' (plural) Not supported.
npm WARN package.json Please pick one as the 'repository' field
npm WARN package.json [email protected] No repository field.
npm WARN package.json [email protected] No repository field.
npm WARN package.json [email protected] No repository field.
npm WARN package.json [email protected] No repository field.
C:\Users\Dmitry\AppData\Roaming\npm
└── [email protected]


C:\ChatServer\Server>npm ls installed express
C:\ChatServer\Server
└── (empty)

How can I solve this problem? (MUST I install it without -g?)

possible duplicate of NodeJS - Unable to import global modules — Evan Carroll, Commented Nov 11, 2013 at 6:46
possible duplicate of NodeJS - How to resolve "Cannot find module" error — BuZZ-dEE, Commented Sep 23, 2015 at 21:30
Possible duplicate of node.js, Error: Cannot find module 'express' — Thusila Bandara, Commented Oct 13, 2017 at 9:26

Golo Roden · Accepted Answer · 2013-06-18 06:56:23Z

320

You need to install Express locally into the context of your application (node_modules folder):

$ npm install express

The reason for this is that applications always look in their local context for any dependencies. The global installation is only for setting up system-wide available binaries, such as unit test runners or bootstrappers or things like that.

With Express, when you install it globally, you get an express binary that can bootstrap an application for you. For more information, type

$ express --help

So, to answer your final question: YES, you need to install it without -g.

answered Jun 18, 2013 at 6:56

Golo Roden

148k99 gold badges309 silver badges437 bronze badges

1

This helped me too. I had winston installed globally, which worked for some reason when starting my app as a normal user, but when starting my app and a system init script it wouldn't work. I fixed it by installing winston locally in the app directory (and adding it to package.json).
– trusktr
Commented Apr 21, 2014 at 2:08
4

you can link a global installed dependency by cd to your project root directory and then use "npm link <some dependency name>"
– khoi nguyen
Commented Sep 29, 2014 at 14:34
14

npm install after you've created your app. It'll install all dependencies.
– user1980175
Commented Mar 24, 2015 at 8:44
Thanks this really helped. Going to node_modules folder and than installing express solved my problem
– Megha
Commented Jul 31, 2016 at 9:17
@Golo Roden Accoding your answer i tried with your solution but it's throwing error : ' npm ERR! tar.unpack untar error C:\Users\VV\AppData\Roaming\npm-cache \express\4.14.0\package.tgz npm ERR! Windows_NT 6.3.9600 npm ERR! argv "C:\\Program Files\\nodejs\\\\node.exe" "C:\\Program Files\\nodejs \\node_modules\\npm\\bin\\npm-cli.js" "install" "express"
– VjyV
Commented Oct 10, 2016 at 9:40

| Show 2 more comments

Mustafamg · Accepted Answer · 2014-11-12 09:51:34Z

23

For me it worked when installed express locally with --save option as follow:

$ npm install express --save

answered Nov 12, 2014 at 9:51

Mustafamg

7545 silver badges20 bronze badges

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Reza Ebrahimi · Accepted Answer · 2013-11-22 10:25:17Z

13

Check if you are not install express module, use this command:

 npm install express

and if your node_modules directory is in another place, set NODE_PATH envirnment variable:

 set NODE_PATH=your\directory\to\node_modules;%NODE_PATH%

answered Nov 22, 2013 at 10:25

Reza Ebrahimi

3,6732 gold badges28 silver badges42 bronze badges

In Windows 10 after the npm install express, it cannot automatically added to node path, you need to manually add the node modules to it.
– Jane
Commented Aug 25, 2017 at 9:25

Add a comment |

Luca Davanzo · Accepted Answer · 2015-11-18 08:11:52Z

5

Golo have explain well the solution, but I might add a clarification:
sometimes node modules are installed in

/usr/local/lib/node_modules

and when you launch node blabla.js modules are searched in

/lib

So a solution is to create a symbolic link:

sudo ln -s /usr/local/lib/node_modules/ /lib/node_modules

edited Nov 18, 2015 at 8:11

answered Nov 18, 2013 at 16:16

Luca Davanzo

21.4k15 gold badges122 silver badges148 bronze badges

1

easier way -> npm link <module>
– Amit G
Commented Apr 8, 2016 at 18:40

Add a comment |

Krishna Ganeriwal · Accepted Answer · 2017-08-29 11:48:02Z

5

Given you have installed node on your system, install Express locally for your project using the following for Windows:

npm install express

or

npm install express --save

You might give it global access by using:

npm install -g express --save

edited Aug 29, 2017 at 11:48

answered Sep 23, 2016 at 12:59

Krishna Ganeriwal

1,96120 silver badges17 bronze badges

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Rahul Gupta · Accepted Answer · 2014-05-09 06:17:34Z

In your case your express module is installed at C:\Users\Dmitry\AppData\Roaming\npm\node_modules\express, but you need to get this module in to your project directory. So you should copy the file the express module folders from C:\Users\Dmitry\AppData\Roaming\npm\node_modules\ to your project directory as : C:\ChatServer\Server\node_modules. If you do not have a folder named 'node_modules' in your project folder, then create it first and paste those files into this folder. This method worked for me on my windows pc. Restart your node server and once again run the command node C:\ChatServer\Server>node server.js. It should work now !!!!

Worked on windows 10 too!
– Victor Michael Kosgei
Commented Dec 6, 2016 at 16:01 — Victor Michael Kosgei, Commented Dec 6, 2016 at 16:01

Nickolay Savchenko · Accepted Answer · 2015-09-02 16:57:48Z

3

On Ubuntu-based OS you can try

sudo apt-get install node-express

its working for me on Mint

answered Sep 2, 2015 at 16:57

Nickolay Savchenko

1,55417 silver badges31 bronze badges

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Adrian Moisa · Accepted Answer · 2017-08-30 22:59:10Z

I had this error in vscode, although the modules where installed. I am using typescript and express. In the server.ts files all the imports had red squiggly underlines. It turns out I had a faulty tsconfig.json file.

{
    "compileOnSave": false,
    "compilerOptions": {
        "module": "commonjs", // Previously this value was `es6`
        "target": "es6",
        "allowSyntheticDefaultImports": true,
        "baseUrl": "public",
        "sourceMap": true,
        "outDir": "dist",
        "jsx": "react",
        "strict": true,
        "preserveConstEnums": true,
        "removeComments": true,
        "noImplicitAny": true,
        "allowJs": true
    },
    "exclude": [
        "node_modules",
        "build"
    ]
}

Alex 75 · Accepted Answer · 2020-07-12 14:02:08Z

2

I had the same error following the example on this book: "Kubernetes Up & Running".
I see many answers suggesting to install express "by hand" but I'm not convinced is the best solution.
Because we are using package.json (I can see it in the logs) and the right way to build the app is running npm install, I added the express dependency in the package.json file.

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

I get the current version with npm search express.

answered Jul 12, 2020 at 14:02

Alex 75

3,1382 gold badges34 silver badges54 bronze badges

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Community · Accepted Answer · 2020-06-20 09:12:55Z

1

create one folder in your harddisk e.g sample1 and go to command prompt type :cd and gives the path of sample1 folder and then install all modules...

npm install express

npm install jade

npm install socket.io

and then whatever you are creating application save in sample1 folder

try it...

edited Jun 20, 2020 at 9:12

CommunityBot

11 silver badge

answered Feb 20, 2014 at 11:38

Dev

272 bronze badges

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Anayatullah Khan · Accepted Answer · 2017-01-07 19:56:19Z

1

go to your application directory and install the express module using the below command npm install express --save then list the all install module using the below command npm ls you will see all the locally install modules.

answered Jan 7, 2017 at 19:56

Anayatullah Khan

112 bronze badges

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user2512153 · Accepted Answer · 2016-11-03 23:55:50Z

0

I hit the same problem. I had express installed globally at /usr/local/bin/. When I do 'npm install', express was not created in node_modules of local directory.

Check if you have file name .npmrc in your $HOME
If it has 'global = true', change to 'global = false'
Now do 'npm install' in application directory. More likely, you should get all package dependent modules installed in node_modules (local) within application directory.

answered Nov 3, 2016 at 23:55

user2512153

1

Add a comment |

Durul Dalkanat · Accepted Answer · 2016-11-26 19:29:06Z

0

sudo brew uninstall node
brew update
brew upgrade
brew cleanup
brew install node
sudo chown -R $(whoami) /usr/local
brew link --overwrite node
sudo brew postinstall node

This worked for me on MacOS X Sierra

answered Nov 26, 2016 at 19:29

Durul Dalkanat

7,3854 gold badges35 silver badges39 bronze badges

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David Castro · Accepted Answer · 2019-10-29 21:21:06Z

0

I'm not proud sharing this, but in my case I had:

 require('express.handlebars')

 //and the correct form is:
 require('express-handlebars'); //Use dash instead.

edited Oct 29, 2019 at 21:21

answered Oct 29, 2019 at 20:57

David Castro

1,88922 silver badges21 bronze badges

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Divesh singh · Accepted Answer · 2021-01-29 01:37:14Z

0

1.first check if express is install at correct location. 2. npm install express (run this command). 3. express will save under your "node_modules" folder

answered Jan 29, 2021 at 1:37

Divesh singh

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