On my system I have both Ubuntu and Windows. On both systems I mainly use Firefox to browse the web. But, I was surprised to see that Firefox runs very smoothly and quickly on Ubuntu than Windows. On Windows, I frequently see Firefox hanging when opening new tabs, while Gmail is loading etc. But, on Ubuntu there were no such problems. One possible problem are addons. I use 5 addons on Windows, whereas on Ubuntu I use only 1. Second main reason why Firefox runs slowly on Windows is that there are many unnecessary entries in about:config. In this article we’ll see how these entries are added and how to remove them to speedup Firefox.
The Cause :
Whenever we install a Firefox addon or toolbar, that addon or toolbar will add entries to about:config. These entries are the preferences of that particular addon and these preferences helps the addon to work correctly. When we no longer needs a plugin we’ll disable it or remove it. Even though we remove plugin from Firefox, their settings are not removed from about:config. Overtime, as we try many addons, many of such entries are created and are left over even after we remove those addons. These left over entries pile up one by one eventually affecting the performance of Firefox like slow startups, frequent hangs etc. This is how Firefox becomes slow overtime.
The Solution :
It’s always easy to solve a problem if we know the cause of that problem. Now that we know the cause, we’ll now try to fix it. In order to remove those unnecessary entries, follow the below steps.
- Enter about:support in Firefox’s address bar and hit Enter. This will open Troubleshooting Information.
- Under Application Basics, open profile directory by clicking on the button Open Containing Folder.
- Now, Firefox’s profile directory will be opened by Windows Explorer.
- Now Close Firefox. If you don’t close Firefox the following steps will now work.
- In this folder, find the file called prefs.js and open it with a text editor. This file is a huge one, so it is better to open it with applications other than notepad, like wordpad or notepad++ etc.
- When you open prefs.js you’ll see many lines like this :
- Just by looking at those lines we can identify to which addon those lines belong to. So, if you find any line which belongs to an unavailable (which is removed) addon, then carefully delete all those lines. After deleting all such lines save the file.
In this way, I’ve found 137 unnecessary entries within few minutes and I removed them all. So, after removing all such entries, open Firefox to experience performance improvements.
The extent of performance gain attained through this method depends on the number of addons you used. If you are a tech-enthusiast who tries lot of addons, then by this procedure you’ll experience huge performance improvements. If you rarely use addons then you won’t find any performance improvement. So, try above walk through to make Firefox run smoother and faster.