Just as your ears might be assaulted by someone’s foul mouth as you walk down the street, you might unwittingly come across some family un-friendly language on a web page. You may not browse to any overtly nasty sites, but on sites that allow unmoderated comments, some people might leave some profanity-laced prose.

The Profanity Filter for Firefox, a Greasemonkey script, can help by actually replacing foul words on web pages with “***”. It actually runs after the page loads, so the original page (including any profanity) is displayed on the screen momentarily before the script replaces any words.


To set up the filter in your Firefox browser:

  1. If not already installed, install the Greasemonkey add-in. (This requires a restart of Firefox.) This add-in uses JavaScript code to change the behavior of web pages. UserScripts.org has dozens of scripts–take a look at what these scripts can do.
  2. Install the script. <--From the page linked here, click the "Install this Script" button.

Greasemonkey Script Install Prompt

At this point, you should be set. Greasemonkey is enabled by default (notice the smiling monkey in the the lower-right corner of Firefox), and the script is installed, ready to replace unsavory language with “***.”

Takeaway: While it is not a perfect tool, the Profanity Filter script is very effective in keeping profanity off your screen. For about 2 minutes of your time, you can help protect your (and your loved ones’) eyes from much of the filthy language browsing sometimes brings.