SlimerJS has several options, that can be indicated on the command line or modified during the execution of the script.

It has also a “profile” system, the same as Firefox, which allows you to launch SlimerJS with different execution context.

Command line options

SlimerJS accepts a number of options on the command line. It accepts the same options as PhantomJS, plus some others. Indicate them before the script filename.

However, all options are not supported yet. And some of them won’t be supported because they don’t make sens with the existing profile system.

For Windows users: if an option does not work, remove the equal sign and the first dash. For example, --proxy=localhost becomes -proxy localhost. You should note also that the command line parsing is done by Firefox, not by SlimerJS.

PhantomJS options    
--config=/path/to/config.json Supported (0.9) indicate a config file
--cookies-file=/path/to/cookies.txt N/A. see profiles  
--debug=[yes|no|true|false] supported Displays debug messages. Supports also other values
--disk-cache=[yes|no|true|false] Supported (0.9) Enable the disk cache or not. By default: disabled
--help or -h Supported Displays help about options
--load-images=[yes|no|true|false] Supported  
--local-storage-path=/path/to/file N/A. see profiles  
--local-storage-quota=number Supported number in Bytes
--max-disk-cache-size=size Supported (0.9) Limits the size of the disk cache (in KB)
--proxy=[address:port|url] Supported (0.9) See below for possible values
--proxy-auth=username:password Supported (0.9)  
--proxy-type=[http|socks5|none] Supported (0.9) See below other possible values
--ssl-protocol=[ssl protocol name] Supported (0.9.5) Indicates the SSL protocol to use. See notes about it below. Default is TLS.
--ssl-certificates-path=/path/to/dir N/A. see profiles  
--version or -v Supported Displays the version of SlimerJS
--webdriver or --wd or -w Supported launch SlimerJS as a driver for Selenium (experimental)
--webdriver=ip:port Supported launch SlimerJS as a driver for Selenium, by indicating the ip and a port (experimental)
--webdriver-logfile=/path/to/logfile Supported sets the log file for webdriver
--webdriver-loglevel=[ERROR|WARN|INFO|DEBUG] Supported sets the log level for webdriver
--webdriver-selenium-grid-hub=url Supported sets the url to the Selenium grid hub

SlimerJS has some specific options. Some of them are options of Firefox

Options specific to SlimerJS    
--error-log-file=file Supported stores all JS errors in the given log file
-jsconsole Supported Open the error console that displays all javascript errors, warning, notices...
-P name Supported Use the indicated profile
-CreateProfile name Supported Create a new profile
-profile path Supported Use the given directory as a profile
--user-agent=string Supported Set the default value of webpage.settings.userAgent
--viewport-width=number Supported Set the default value of webpage.viewportSize.width
--viewport-height=number Supported Set the default value of webpage.viewportSize.height

About debug

With the --debug option, SlimerJS displays many messages about what happened during the execution of your script: network events, page loading, sendEvent calls, configuration values, command line parameters..

SlimerJS accepts a value other than true/false/yes/no for --debug. You can indicate what to display.

Example: --debug=pageloading,netprogress.

Available keywords are:

  • page: show calls of some webpage API
  • pageloading: show calls of webpage listeners about resource loading and page loading
  • netprogress or net or network: show internals network events
  • config: show configuration values
  • cli: show command line parameters for the script
  • errors: show gecko errors (javascript errors ...). only for Firefox 25+

About proxy configuration

You can indicate an HTTP proxy configuration or a SOCKS proxy configuration: --proxy-type=socks5 or --proxy-type=http. For this both type, the host name and the port should be indicated with the --proxy= option: --proxy=host:port

SlimerJS supports also some specific values for --proxy-type:

  • auto: SlimerJS tries to detect automatically proxies

  • system: SlimerJS uses the proxy configuration set into the operating system. Under linux, Firefox is using proxy configuration stored into Gnome settings or GConf. Note that the use of the http_proxy environment variable does not work.

  • config-url: SlimerJS uses the proxy configuration set into a file. The HTTP or file:// URL

    of this file should be indicated with the --proxy= option.

About SSL protocols

Firefox does not support SSLv2 protocol. It supports only SSLv3 to latest TLS version (v1.2 for Gecko 35). However, SSLv3 is deactivated because of a vulnerability in the SSLv3 protocol ( POODLE ).

When you use the --ssl-protocol flag, you indicates to use the indicated protocol. No other will be used. Except the value any, to use SSLv3 to TLSv1.2, or TLS to use any TLS version. In these case, the browser will use the best protocol supported by the web server.

Possible values are: SSLv3, TLSv1, TLSv1.1, TLSv1.2, TLS, any.

Configuration file

A configuration file could be given with the --config option.

This file does contain a JSON object. Each of its properties correspond to a configuration parameter with a de-dashed and camel-cased name.

    "maxDiskCacheSize": 123

Some options are not supported in the configuration file, since they are processed before the execution of the core of SlimerJS: --help, --version, -jsconsole, -P, -CreateProfile, -profile,

Options in your script

Values of some options are available through the phantom object and the webpage object.

phantom.defaultPageSettings is an object that contains this following properties:

    allowMedia: true,                       // value of --allow-media
    javascriptEnabled: true,
    loadImages: true,                       // value of --load-images
    localToRemoteUrlAccessEnabled: false,   // value of --local-to-remote-url-access
    XSSAuditingEnabled : false,
    webSecurityEnabled: true,               // value of --web-security
    javascriptCanOpenWindows: true,
    javascriptCanCloseWindows: true,
    userAgent: 'SlimerJS',
    userName: undefined,
    password: undefined,
    maxAuthAttempts: undefined,
    resourceTimeout: undefined

phantom.defaultPageSettings cannot be modified by your script.

The property settings of a webpage object contains the same object, except that it can be modified. The default value of settings is equal to phantom.defaultPageSettings.

Note that even if settings and phantom.defaultPageSettings are usable, only few settings are taken account by webpage objects: javascriptEnabled, loadImages and userAgent.


A profile is a directory where Firefox (and so SlimerJS), store many things:

  • preferences (Mozilla options)
  • cache files
  • storage of data like localStorage or IndexedDb
  • cookies
  • etc...

By default, SlimerJS create a temporary profile each time you launch it. This profile is deleted at the end of the execution. It allows to launch several SlimerJS instances at the same time: they don’t share same profile files.

If you want to use a persistent profile (to reuse same preferences, same cookies, localstorage etc stored during a navigation), you have to create a specific profile and to indicate it.

slimerjs -CreateProfile myNewProfile

It will create a directory in $HOME/.innophi/slimerjs/. Then to use this new profile, use the -P parameter

slimerjs -P myNewProfile  myscript.js