How to Install a Firefox Extension (with screenshots)
One of my favorite features of Firefox is that users can modify it with extensions. No matter what it is you want to do or change about a web page, there is undoubtedly an extension out there already that does it for you. Someone has gone to through all the hard work and now all you have to do is install it to reap the benefits. I know it is arrogant of me to say so, but I do not understand how people surf the Internet without using extensions that simplify common tasks and improve the way websites work.
This guide is intended for beginners
Why Use Extensions?
Firefox extensions help you get things done. They can reduce repetitive tasks to something simple and improve your web experience. Here are some examples of popular Firefox extensions:
- Block *all* ads on the Internet with the Ad Block Plus extension (and the automatic Ad Block updater).
- Choose the correct dictionary for your language (e.g. I use Canadian English).
- Display your local weather.
- Download PDFs instead of having to read them in the oh-so-slow Acrobat Reader.
- Download videos from YouTube and all of those other video web sites.
- View web pages using Internet Explorer *inside* of Firefox!
- Save your tabs and reopen tabs you’ve accidentally closed.
- Control your music player from inside of Firefox.
- Synchronize your Firefox bookmarks across multiple computers.
- Add a button to access your Google Bookmarks.
- Save web pages to del.icio.us.
- Access Flickr even if it is banned.
- Surf the web as if you were surfing TV with StumbleUpon and StumbleUpon Video.
- Easily switch between different proxy settings if you use your laptop at work and at home.
The real power of Firefox is in the user community around it who builds all these cool toys. If you only use one extension, Ad Block Plus will revolutionize your web surfing. I’m always so surprised when I access web sites on a browser without Ad Block Plus and see all of the crap that gets in the way. Installing extensions can be addictive, but it’s a good idea to pick 5 to 10 of the best ones and stick with those.
Installing a Firefox Extension
I hope I’ve convinced you of the value in Firefox extensions. A little goes a long way. Here is a walkthrough of how to install them.
1. Find an extension you want to install
Most extensions can be found on the Mozilla Add-ons website. For this example I’ll be installing the Greasemonkey extension. Greasemonkey is a bit different than other extensions, in that it’s kind of a parent extension. With Greasemonkey installed you’ll be able to install all other kinds of baby extensions (called userscripts) to tweak web sites even more.
2. Click on the install link
Firefox extensions end with the .XPI suffix. When you click on an .XPI file, Firefox knows how to open and install it for you. The official Mozilla Add-ons page shows all of the links with a green Install This button. If you are installing an extension from somewhere else it might look different.
3. Click on the Install Now button
When Firefox recognizes that you are installing an extension it brings up a box asking you if you want to install it. Click Install Now.
4. Restart Firefox to Finish Installation
The installation will not be complete until you restart Firefox. The good news is that Firefox will remember all the pages you are viewing right now, so go ahead and click on the Restart Now button.
Thinks don’t always go the way you want them to. Leave a comment if you have any other further questions and I’ll expand this section.
Q1: How do I find out what extensions I have installed?
If you go to Tools >> Add-ons you’ll find a list of all of your installed extensions. From that list you can configure, enable, disable, check for updates, and uninstalled individual extensions.
Q2: I click on the .XPI file but it downloads the file instead of asking me to install. Help!
This is because the web server with the .XPI is improperly configured. Save the file to your computer and then open it using File >> Open. You will get the normal prompt to install the file.
Q3: I want to download a file from somewhere other than Mozilla Add-ons.
Here is an example of downloading an extension from the popular technology blog Lifehacker.
After you click on the download link Firefox will display a yellow status bar at the top of your web browser (but still underneath your toolbar) because it doesn’t know if you trust extensions from lifehacker.com.
Click on the Edit Options button and it will bring up a window asking you to confirm if you trust this site for installing add-ons. Click on the Allow button followed by the Close button.
Then click on the original download link again and your install will proceed as normal.