J Dev 7

How To Speed Up Firefox 8

Before tweaking, check for any add-ons that you no longer use or could do without – the more you have installed the slower and less stable Firefox will become:

In the Firefox menu bar click Tools then Add-ons to open the Add-ons Manager. Now click on Extensions and if you no longer need an extension then remove it or at least disable it. Restart Firefox when you have finished.

All the following tweaks are done by changing or adding values to the Firefox configuration page known as about:config. To be on the safe side, you should make a note of the ‘before’ and ‘after’ values of each tweak and (highly recommended) backup the Firefox preferences file that contains all the configuration options in case you want to revert back to your original settings:

The configuration file is called prefs.js and can be found in the following place in your operating system drive (usually C: drive):

\Documents and Settings\<username>\Application Data\Mozilla\Firefox\Profiles\<profile ID>.default\ in Windows XP or

\Users\<username>\AppData\Roaming\Mozilla\Firefox\Profiles\<profile ID>.default\ in Vista and Windows 7.

You may need to show hidden files to view these folders. Copy the prefs.js file to another location on your hard drive whilst Firefox is closed – you could then copy it back (whilst Firefox is closed, replacing the problematic version) if you encounter any problems with Firefox after applying these tweaks.

Tweaking Firefox 8

Open Firefox and type about:config in the address bar and press Enter. Click the box warning “I’ll be careful I Promise” to reveal a long list of preferences used in Firefox.

• To change a preference which is an integer (number) or a string (text) you need to double click on the preference name and you will be prompted for the new value. If you double click on an entry that has a Boolean (true or false) value, the entry will switch from true to false or vice versa – double clicking again will revert it to its original value.

• To add a preference (if the preference name is not already listed in your about:config page) you need to 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).

Changing Preferences

Change the following preferences to the new values shown. If the preference is already set to this value then skip it and move on the next. If the preference does not exist then you need to add it:

browser.display.show_image_placeholders: false

Stops the display of placeholders while images are loading to speed up the page. Default is True

content.notify.backoffcount: 5     (New, You Must Add It!    Use Filter For Faster Search)

Sets the maximum number of times the content will do timer-based reflows to 5. After this, the page will only reflow once it is finished downloading. This is a new integer value. Default is -1 (no limit)

content.notify.interval: 120000     (New, You Must Add It!    Use Filter For Faster Search)

Sets the minimum amount of time to wait between periodic reflowing of the page to 0.12 seconds – stops Firefox becoming slow by reflowing too frequently. This is a new integer value. Default is 120000

content.max.tokenizing.time: 360000     (New, You Must Add It!    Use Filter For Faster Search)

Sets the maximum amount of time Firefox will be unresponsive while rendering pages – set to 3 times the content.notify.interval above. This is a new integer value. Default is 360000

content.notify.ontimer: true     (New, You Must Add It!    Use Filter For Faster Search)

Ensures Firefox does not reflow pages at an interval any higher than that specified by content.notify.interval above. This is a new Boolean value. Default is True

content.interrupt.parsing: true     (New, You Must Add It!    Use Filter For Faster Search)

Sets Firefox to interrupt parsing a page to respond to UI (user interface) events to prevent it becoming unresponsive until parsing is complete. This is a new Boolean value. Default is True

content.switch.threshold: 750000     (New, You Must Add It!    Use Filter For Faster Search)

Sets the number of microseconds of inactivity that puts Firefox into low frequency interrupt mode. This is a new integer value. Default is 750000

network.prefetch-next: false

Stops Firefox automatically prefetching (loading) the contents of pages linked to by the page you are viewing – in most cases you will never visit those links so this time is wasted and it is a security risk because you are unwittingly downloading (possible virus/adult) content only linked to by the current page but which you have not chosen to load. Default is True

network.http.max-persistent-connections-per-server: 8

Increases the maximum number of persistent connections per server which can help speed up loading of multimedia rich sites. Default is 6

network.http.pipelining: true

Can send multiple requests to a server together in order to speed up loading of webpages. This is not supported by ALL servers – some servers may even behave incorrectly if they receive pipelined requests. Default is False

network.http.pipelining.maxrequests: 8

Sets a maximum number of multiple requests that can be pipelined to prevent overloading the server. Higher values will cause a delay before the first request completes but will make the last request complete sooner. Higher values will also cause more of a delay if a connection fails. The maximum value is 8. Default is 4

network.dns.disableIPv6: true

Disables IPv6 DNS lookups to prevent a significant delay with poorly configured IPv6 servers. Default is False