SlimerJS with NPM support.

Usage no npm install needed!

<script type="module">
  import slimerjsCore from '';


SlimerJS + NPM Fork

This is a temporary fork of SlimerJS until proper NPM support is added upstream[1]. At that time this package will likely be discontinued. It's only being developed in order to allow developers to be unblocked by having a package on NPM.



SlimerJS is a scriptable browser. It allows you to manipulate a web page with an external Javascript script: opening a webpage, clicking on links, modifying the content... It is useful to do functional tests, page automation, network monitoring, screen capture etc.

It is a tool like PhantomJs, except that it runs Gecko instead of Webkit, and it is not (yet) natively headless. However, it can be headless with the use of xvfb under Linux (but not on MacOS).

SlimerJS provides the same API of PhantomJS. The current version of SlimerJS is highly compatible with PhantomJS 1.9. See current release notes in docs/release-notes-*.rst, and read the compatibility table to know the implementation level.

The main goal of SlimerJS is to allow to execute all scripts developed for PhantomJS. So you could use tools like CasperJS. In fact, CasperJs 1.1 and higher can be executed with SlimerJS!

SlimerJS is not only a PhantomJS clone, it contains also additional features.

Technically, SlimerJS is a XUL/JS application that is launched with Firefox.


Follow us on twitter: @slimerjs

Ask your questions on the dedicated mailing list.

Or discuss with us on IRC: channel #slimerjs on

Install SlimerJS, executing a script...

See documentation into the docs/ directory into the source code, or read it on the web site


The goal for a first major stable release 1.0 is to have a full implementation of the API of PhantomJS 1.9.x and 2.1, with the support of Coffee scripts and Ghost Driver.

FAQ and contribution

Read the faq into the website/faq.html file or on the website.