Greasemonkey 0.9.13

Browser extension for Firefox that lets you make quick website edits

  • Category:


  • Version:


  • Works under:

    Windows ME / Windows 7 / Windows Vista / Windows XP / Windows 2000 / Windows 8

  • Also available for:


  • Program available in:In English
  • Program license:Free
  • Vote:
    6.1 (102)

Greasemonkey is a Web browser extension for Firefox, Web, Seamonkey, Flock and Songbird that allows end users to install community-created scripts that enable the ability to add new functionality, change existing behaviors and completely customize the appearance of the websites that they visit on a regular basis.

In addition to adding new features to the websites that you know and love, Greasemonkey scripts can also be used to fix annoying or troubling website issues. For instance, display errors or terrible design oversights can be eliminated without waiting on the developers to make the changes, if they’re ever made at all! If you find that a particular website’s color scheme is hard on your eyes, it is simple to download and install a script that will apply your desired changes, and make them permanent as well.

Thousands of pre-made user scripts are ready to use, with new and useful code being written and released all the time. For the most popular websites, hundreds of scripts are available that can take your Web browsing experience to the next level. If you enjoy shopping for deals online, you can add functionality to browse multiple listings side-by-side to compare prices and availability with just a click. If you are into keeping up with your social circle, you can easily install a script that notifies you when someone unfriends you on a social network. While browsing through the various script directories, you will even run into ideas you never would have dreamed of! Who knew that combining all of your favorite online video sites into one easy-to-use portal would make all the difference?

With several centralized databases of user made scripts at your disposal, there will be no problem finding something that meets your specific needs. If you know how to program Javascript, it is very possible to create your own personalized script capable of doing anything that you can think of. While Greasemonkey has only been released for a few specific browsers, the scripts are cross compatible with most modern web applications, though some of the proprietary features may be disabled.

The add-on is easy to install, as are the scripts that make it useful. By simply browsing the database and clicking on the feature that you want to install, the script will be active immediately on the relevant websites. In most cases, you will not even need to restart your browser!

If you are looking to fix some common annoyances, or you just want to customize the Web a little more to your liking, then Greasemonkey is the extension for you. With its plug and play interface, everyone from computer novices to IT professionals will find something useful to install.


  • Very simple to install and use
  • Active scripting community
  • Enables you to customize the entire web


  • Not available for Chrome
  • Cannot interact with I/O functions or toolbars

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