Serverless Plugin Browserifier

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Serverless Browserifier Plugin

serverless NPM version digitalmaas NPM downloads standardjs

A Serverless v1 plugin that uses Browserify to bundle your Node.js Lambda functions.

This project has been forked from the original serverless-plugin-browserify by Ryan Pendergast and published under a different name.


Lambda functions with smaller code start and run faster.

With the example package.json and javascript code below, the default packaging for Node.js lambdas in Serverless produces a zip file that is 11.3 MB, because it blindly includes all of node_modules in the zip package.

This plugin with 2 lines of configuration produces a zip file that is 400 KB!

  "dependencies": {
    "aws-sdk": "^2.6.12",
    "moment": "^2.15.2",
    "request": "^2.75.0",
    "rxjs": "^5.0.0-rc.1"
const Rx      = require('rxjs/Rx');
const request = require('request');

Even if you choose to manually prepare your packages with package[include|exclude], you will still have to take care of that for each single function individually, and manually. This is specially hard after npm 3, due to dependency tree flattening.

Also, AWS Lambda has an account-wide deployment package size limit.

Mind that aws-sdk-js now officially supports browserify. Read more about this in on this article.


From your target serverless project, run:

npm install serverless-plugin-browserifier --save-dev

Add the plugin to your serverless.yml file and set package.individually to true:

  - serverless-plugin-browserifier
  individually: true

The property package.individually must be set because it makes configuration more straightforward, and if you are not packaging individually size is not a concern of yours in the first place.


For most use cases you should NOT need to do any configuration. You can, however, introduce custom configuration.

The base config for browserify is read from the custom.browserify section of serverless.yml. All browserify options are supported (most are auto configured by this plugin). This plugin adds one special option disable which if true will bypass this plugin.

The base config can be overridden on a function-by-function basis. Again, custom.browserify is not required and should not even need to be defined in most cases.

    #any option defined in

      name: ${self:provider.stage}-${self:service}-pageGet
      description: get user
      handler: users/handler.hello      
          - ./someBig.json  #browserify can't optimize json, will take long time to parse for nothing      

If you find a package that is not supported or does not behave well with browserify, you can still use function level package.include to include extra modules and files to your package. That said, you are encouraged to verify if you specific case can be dealt with by leveraging all available browserify options in your serverless.yml custom browserify section.


When this plugin is enabled, and package.individually is true, running serverless deploy and serverless deploy -f <funcName> will automatically browserify your Node.js lambda code.

If you want to see more information about the process, simply set SLS_DEBUG=*. Example:

$ export SLS_DEBUG=*
$ sls deploy function -v -f usersGet


Should I use Webpack instead of this plugin?

Browserify, in general, supports more modules, optimises better (generates smaller bundles), and requires less configuration. Webpack is an amazing tool, but it comes with several extras that are not really needed within a pure Node.js environment.

What about uglification?

You should be able to use uglify-es through uglifyify.

And what about babel?

I believe that babelify should do the trick, although I don’t see any reason for it. AWS Lambda already supports Node.js 6.10, with enough ES-next goodies that allows us to avoid transpilers.


MIT License.
For the complete information, please refer to the license file.