1. Update Firefox : If you’re not running the latest version you are more at risk from unfixed vulnerabilities and will not benefit from the latest technical improvements:
Select Firefox (or Help from the menu bar) then ‘About Firefox’ and press the ‘Check For Updates’ button. Apply updates if available then retry – the Check message should confirm ‘Firefox is up to date’.
2. Remove extensions you do not need: The more extensions you have enabled, the slower and less stable Firefox may become:
Select Firefox (or Tools from the menu bar) then Add-ons to open the Add-ons Manager. Click on Extensions and, if you no longer need an extension, Remove it – if in doubt, at least Disable it.
3. Update extensions: The easiest way to always keep extensions up to date is to open the Add-ons Manager and click the Tools ‘cog’ at the top then select (tick) ‘Update Add-ons Automatically’.
To perform a manual update, click the Tools ‘cog’ then select ‘Check for Updates’ and apply any that are found.
4. Disable plugins you do not need : As with extensions, the more plugins you have enabled, the more problems Firefox may encounter:
Open the Add-ons Manager. Click on Plugins and, if you do not need a plugin, disable it. If you disable a specific plugin and ever do visit a site that needs it, just re-enable it.
5. Update plugins: Plugins from third parties such as Adobe and Oracle are often targeted by malicious websites so it is important to keep them up to date.
7. Changing preferences
To change a preference, if it is an integer (number) or a string (text), double click on the preference name and you will be prompted for the new value. If it is a Boolean (true or false) value, double click the entry to switch from true to false or vice versa.
To add a preference (if the preference name is not already listed in your about:config page) right click on an empty space in the about:config window and choose New followed by String, Integer or Boolean depending whether the value of the preference is text (String), a number (Integer) or true/false (Boolean)
Backup the Firefox preferences file that contains all these options first – in case you want to revert back to your original settings:
The configuration file is called prefs.js and is located in the system partition (usually C:\ drive):
In Windows XP
\Documents and Settings\<username>\Application Data\Mozilla\Firefox\Profiles\<profile ID>.default\
In Vista and Windows 7
You may need to show hidden files to view the folder. Close Firefox first and then copy the prefs.js file to another location on your hard drive for backup.
Open Firefox and type about:config in the address bar then press Enter
Click the “I’ll be careful I Promise” warning button to reveal a long list of preferences.
Search for preferences:
Change or add the following preferences to the new values shown.
Stops the display of placeholders while images are loading to speed up the page. Default is True
Disables all tab animation features (e.g. when you click the ‘New Tab’ (+) button) to make the tab interface feel quicker. Default is True
This setting can automatically prefetch (load) the contents of pages linked to by the page you are viewing e.g. to load the homepage in the background, making it quicker for you to view next if you want to. To take advantage of increased speed when browsing websites which use prefetch, keep this setting at the Default which is True.
Increases the maximum number of persistent connections per server which can help speed up loading of multimedia rich sites. Default is 6
If you use broadband, you can make webpages load even faster in Firefox by using this "pipelining". Normally the browser will make one request to a web page at a time. When you enable pipelining it will make several at once, which can speed up page loading.
Now close Firefox and re-open it to apply all the tweaks.
8. Enable Click To Play
Plugins (e.g. Flash Player) can consume significant resources and slow down page loading. Click to Play configures all plugins to only load on click which can dramatically increase the speeds of media rich pages.
This feature is not enabled by default at the time of writing but you can enable it via a simple change in about:config – see Activating Click To Play (half way down the page). You can also Add a Button to the Navigation Toolbar to quickly switch Click To Play on or off at the press of a button.
If you have set the option to ‘Show my windows and tabs from last time’ (in Options > General) when Firefox starts, it may have to load multiple tabs – keen users may have dozens of open tabs which Firefox has to load in full each time it starts. This can really slow down the time it takes to open Firefox – a common complaint. To greatly speed up the loading process:
In Options >Tabs tick the ‘Don’t load tabs until selected’ box and press OK – this menu option will still open all your saved tabs when Firefox starts but will only load the current tab which can save a lot of time