Webpack 1.x/2.x plugin for analyzing internal processes, state and structure of bundles.



Webpack 1.x/2.x plugin for analyzing internal processes, state and structure of bundles. Built on rempl.


npm install webpack-runtime-analyzer --save-dev


1) Add plugin to your webpack config:

var RuntimeAnalyzerPlugin = require('webpack-runtime-analyzer');

// ...

plugins.push(new RuntimeAnalyzerPlugin());

2) Start rempl server:


Also, you can use the GUI to control rempl server.

3) Start building in a watch mode (> wabpack --watch or > webpack-dev-server) then open http://localhost:8177/ in your browser to see UI.

Try the example to see how it works:

cd example
npm i
npm run dev

Key features


The list of the modules and the assets is always at hand.


Left list contains all modules that included in your bundle.

Right list contains building output (bundles, chunks, static, etc).

Dependency graph

Take a look at the dependencies of the modules and at the modules stats.

Dependency graph

Module types

There are a few basic module types: - normal - module that you are requiring with require(...) - context - complex module that unites other modules when you are using require.context(...)

Some modules can be marked as entry. It means that this module is declared in entry-section in you webpack-config.

Module is separated by file types (scripts, templates, styles, etc). Every file type has a different color. You can see these colors at the nodes of graph or at the color-bar above the graph.

You can hover mouse cursor at the nodes of graph or at the color bar sections and see an additional module-info or a file type statistic.


  • zooming graph with mouse/touchpad scrolling
  • changing graph position with drag and drop on the white field.
  • changing rendering speed by sliding speed slider
  • pause/resume graph rendering with space-key

File size map

Look at the file map and find out why your bundle is so big.

File size map

Realtime analyzing

Analyzing process is performing in realtime.

Realtime analyzing

Working with a huge bundles

In a huge bundles there are many modules that are useless for analyzing.

For example, look at the AST Explorer bundle:

AST Explorer modules graph

In this case graph is not usable, moreover overloaded graph decreases rendering performance.

You can enable Hide 3rd party modules in the Options menu to hide modules that isn’t requiring your project-modules.

So, modules list, graph and file map will be contain only modules that requiring your project-modules.

AST Explorer modules graph with hidden 3rd party modules

Hide 3rd party modules is enabled by default.

Webpack 1.x support

All features is working correctly with webpack 2.x and 1.x

Plugin config

If you don’t want to use default plugin config, then you can specify your own config:

new RuntimeAnalyzerPlugin({
    onlyWatchMode: true,
    ui: fs.readFileSync('/path/to/ui/bundle.js', 'utf-8'), // packed UI bundle (js + html + css + etc...)

onlyWatchMode: Boolean

Activate plugin only in a watch mode (> webpack --watch or > webpack-dev-server)

If onlyWatchMode is false then the plugin will be activated in a normal (> webpack) and in a watch mode (> webpack --watch or > webpack-dev-server). It means that normal building process will not be terminated after finish because the plugin is holding a permanent connection to the rempl server. The only way to terminate building process is ctrl+c like in a watch mode.

true by default.

UI customization

The UI built on basis.js framework.

  • Clone this repo
  • Make the changes in src/ui
  • Run npm run build to build the UI bundle to the dist directory
  • Set an absolute path to built UI bundle in the ui plugin option



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