Performance testing tool for Responsive web designs.
HTML JavaScript CSS
Latest commit 274ebda Apr 20, 2016 @jfsiii jfsiii committed with lafikl Prevent JS errors on "Fetch" type (#16)
* Prevent JS errors on "Fetch" type

* Maintain alphabetic sorted keys


Performance testing for Responsive web design websites.


  • Emulate mobile devices, desktop, tablets.
  • Find unused/hidden elements
  • Find unused images
  • Calculate page weight
  • Track requests




npm install rwdperf -g

CLI Usage

First you need to start chrome with these flags (Mac)

sudo /Applications/Google\\ Chrome --remote-debugging-port=9222 ----disable-cache

NOTE You can do the same for other OS, just change the path to chrome (e.g chrome.exe in Windows)

then start another session and enter this command

rwdperf -l --width 400 --height 300 -m true -d 2 -s 2 -u "Mozilla/5.0 (iPhone; CPU iPhone OS 7_0 like Mac OS X; en-us) AppleWebKit/537.51.1 (KHTML, like Gecko) Version/7.0 Mobile/11A465 Safari/9537.53"

List of all options

Usage: rwdperf [options]


  --help                         output usage information
  -V, --version                  output the version number
  -l, --link <val>               Link to be tested
  -p, --port [val]               set a port, defaults to 3000
  -m, --mobile                   Emulate mobile
  -e, --emulateViewport          Emulate viewport, defaults to true
  -d, --deviceScaleFactor [val]  Device scale factor, defaults to 1
  -s, --scale [val]              scale, defaults to 1
  -w, --width <val>              Viewport width
  -h, --height <val>             Viewport height
  -u, --userAgent <val>          Override user-agent
  -j, --json                     Return results as JSON

API Usage

First you need to start chrome with these flags (Mac)

sudo /Applications/Google\\ Chrome --remote-debugging-port=9222 ----disable-cache

then you can consume that directly from your code.

var Rwdperf = require('rwdperf');

new Rwdperf({
  link: "",
  mobile: true,
  emulateViewport: true,
  deviceScaleFactor: 1,
  scale: 1,
  width: 400,
  height: 500,
  userAgent: null,
  cb: handler

function handler(err, data) {
  if ( err ) return console.log(err);

  // all worked out! do amazing stuff with the data...


  • Find downscaled images
  • unused CSS
  • Test multiple urls
  • Add pre-configured device metrics (e.g iPhone 6)
  • Run chrome through the tool itself #6