PhantomJS and confess make it possible to measure your webapplication performance via command-line.

Precondition

• PhantomJS is installed
• confess is downloaded

Preparation

If your PhantomJS version >= 2.0, phantom.args is deprecated! “TypeError: undefined is not an object” You have to make a quick hack inside the confess.js file.

# add in top of file
var system = require('system');

# replace all
phantom.args
# by
system.args

# change
var a = 0;
# into
var a = 1;

Run the performance measurement

# change to folder with confess.js and config.json
$ cd /path/to/folder

# generation of an appcache manifest
$ phantomjs confess.js <URL> appcache

# run performance measurement
$ phantomjs confess.js <URL> performance

Note: By default the results go to stdout, but you can pipe into a file!