Take the Ghacks logo for instance. You will notice that resizing the window in Firefox after loading the image will reduce the size of the image automatically; Firefox resizes the image dynamically.

If the browser window is large enough the image is shown in its original size.

If the browser window is resized, the image is resized dynamically as well.

Firefox has a configuration setting for that. To make the change enter about:config in the Firefox address bar. First time users need to click the I’ll be careful button.

Enter the parameter browser.enable_automatic_image_resizing in the filter list and double-click it to change the value from true to false. Firefox will dynamically resize images if the value is set to true. A value of false will show the images always in their original size regardless of the browser window size.

The change is enabled immediately. Open tabs need to be reloaded once for the change to become active though.

Why would someone want to make the change? It makes sense for very large images, that exceed the screen resolution. Users who want to view those images in their original size need to download them to the computer to do so, as Firefox resizes the images automatically. Making the preference change allows those users to view the images directly in the web browser.

There are a few things that Firefox users can to do make Firefox start faster. There is the Firefox preloader application that loads on system start, the Firefox extension Bar Tab which loads tabs on demand and not all together on startup, cleaning the Firefox preferences file, the SpeedyFox software for Windows, or Vacuum Places add-on to optimize the SQLite databases used by the browser.

Long time Ghacks reader OAlexander just emailed me another tip to make Firefox start faster that I have not heard about before. He mentioned that he removed excess locales from his installed extensions and noticed that Firefox would start up noticeable faster.

Firefox extensions often come with multiple locales to provide users from all over the world with information in their own language. Most users usually only need one or maybe two of the locales. It appears however that all locales are loaded on startup when the extension is loaded (Can anyone confirm this?)

So, to make Firefox start up faster users would have to delete excess locales from the Firefox extensions. An unzip software like 7-Zip is required for that operation. I explain how it is done with 7-Zip.

Make Firefox Start Faster

The first task is to locate the Firefox profile directory, which is the directory where the extensions are stored in. Firefox 3.6 and up users can click on Help > Troubleshoot Information to launch the file browser of the system with the profile folder as the selected folder.

Before we start modifying anything we need to backup the extensions folder. This is just a precaution, but it is always better to have an option to restore a previous state.

Open the extensions folder and take a look around. Some extensions are stored in folders, while others are stored in .xpi files. The folders are basically unzipped xpi files, so no need to worry about the differences.

What you need to do now is to fire up your unzip software and navigate to the Firefox profile folder. 7-Zip users can copy the file path from the system file browser and paste it into the path field in 7-zip. Make sure you close Firefox at this point, otherwise you will not be able to remove content from the extensions since they are in use when Firefox is open.

I suggest to work your way from top to bottom, starting with the xpi files and not the folders. Simple double-click on an xpi file to open its contents in 7-Zip. You will notice that they have a similar structure as those folders in the extensions root folder.

The path to the locales is always the same: Extension root folder > chrome > locale > filename.jar

Follow the path. Once the local folder is the root folder you may notice that multiple locales are provided by the Firefox add-on. You may now select all but the locales that you want to use. Press delete afterwards to delete them from the extension. Confirm that you want to delete the folders and files.

Now switch back to the extensions directory and repeat the process for all installed extensions. The folders are handled the same way.

Once all locale folders that are not needed have been removed it is time to start Firefox to see if the modification has made a difference. The effect depends largely on the installed extensions. Users with dozens of extensions may see a big decrease in startup time.

There is one problem though that needs to be mentioned. It is likely that extension updates will add the locale folders again to the extension. Which means that Firefox users need to delete the locale folders again whenever an extension gets updated.

Did you try this tip? What was the result on your system? Have another tip to speed up Firefox? Let everyone know in the comments.

You could open the Firefox profile folder, locate each add-on and check the disk space individually. This may take some time, especially if lots of add-ons are installed and used in the browser.

An alternative was recently posted in the Mozillazine forums. This can be used to display add-on sizes directly in the Firefox web browser.

The user Bluefang has posted code for Firefox 3.6 and Firefox 4. Here is how you display the add-on sizes in the browser:

• Copy the code from the Mozillazine forum. We have taken the liberty to attach the code to this post as well.
• Open the Error Console in Firefox. You can do that by pressing Ctrl-Shift-J, or clicking on Tools > Error Console in the menubar.
• Paste the code for your browser version into the Code row in the error console and click the Evaluate button afterwards.
• A new window opens that displays all installed extensions, plugins and userscripts. Sizes are only displayed for extensions. The size is shown in Bytes.

Firefox 4 code

const CI = Components.interfaces;
const CC = Components.classes;

function computeSizeRecursive(file)
{
file.QueryInterface(CI.nsIFile);
if(file.isSymlink())
{
return 0;
}

var size = file.fileSize;
if(file.isDirectory())
{
var files = file.directoryEntries;
while(files.hasMoreElements())
{
size += computeSizeRecursive(files.getNext());
}
}
return size;
}

Components.utils.import("resource://gre/modules/AddonManager.jsm");
AddonManager.getAllAddons(function(addons)
{
var addonData = "data:text/html,"
+ "<!DOCTYPE html>"
+ "<html lang=\"en\">"
+ " <head>"
+ " <title>"
+ " Additional Addon Information"
+ " </title>"
+ " </head>"
+ " <body>"
+ " <table>"
+ " <tr>"
+ " <td>"
+ " ID"
+ " </td>"
+ " <td>"
+ " Name"
+ " </td>"
+ " <td>"
+ " Size"
+ " </td>"
+ " </tr>";

addons.forEach(function(addon)
{
addonData += ""
+ "<tr>"
+ " <td>"
+ " " + addon.id
+ " </td>"
+ " <td>"
+ " " + addon.name
+ " </td>"
+ " <td>"
+ " " + ((addon.getResourceURI)
? computeSizeRecursive(addon.getResourceURI()
.QueryInterface(CI.nsIFileURL).file)
: "Unknown")
+ " </td>"
+ "</tr>";
});

addonData += ""
+ " </table>"
+ " </body>"
+ "</html>";

var windowManager = CC['@mozilla.org/appshell/window-mediator;1']
.getService(CI.nsIWindowMediator);
var win = windowManager.getMostRecentWindow("navigator:browser");
win.open(addonData, "", "");

});

Firefox 3.6 Code

const CI = Components.interfaces;
const CC = Components.classes;

function computeSizeRecursive(file)
{
file.QueryInterface(CI.nsIFile);
if(file.isSymlink())
{
return 0;
}

var size = file.fileSize;
if(file.isDirectory())
{
var files = file.directoryEntries;
while(files.hasMoreElements())
{
size += computeSizeRecursive(files.getNext());
}
}
return size;
}

var Application = CC["@mozilla.org/fuel/application;1"].getService(CI.fuelIApplication);

var addons = Application.extensions.all;

var extDir = Components.classes["@mozilla.org/file/directory_service;1"]
.getService(Components.interfaces.nsIProperties)
.get("ProfD", Components.interfaces.nsIFile);
extDir.append("extensions");

var ios = Components.classes["@mozilla.org/network/io-service;1"]
.getService(Components.interfaces.nsIIOService);

var addonData = "data:text/html,"
+ "<!DOCTYPE html>"
+ "<html lang=\"en\">"
+ " <head>"
+ " <title>"
+ " Additional Addon Information"
+ " </title>"
+ " </head>"
+ " <body>"
+ " <table>"
+ " <tr>"
+ " <td>"
+ " ID"
+ " </td>"
+ " <td>"
+ " Name"
+ " </td>"
+ " <td>"
+ " Size"
+ " </td>"
+ " </tr>";

addons.forEach(function(addon)
{
var ext = extDir.clone();
ext.append(addon.id);

addonData += ""
+ "<tr>"
+ " <td>"
+ " " + addon.id
+ " </td>"
+ " <td>"
+ " " + addon.name
+ " </td>"
+ " <td>"
+ " " + ((ext.exists())
? computeSizeRecursive(ext)
: "Unknown")
+ " </td>"
+ "</tr>";
});

addonData += ""
+ " </table>"
+ " </body>"
+ "</html>";

var windowManager = CC['@mozilla.org/appshell/window-mediator;1']
.getService(CI.nsIWindowMediator);
var win = windowManager.getMostRecentWindow("navigator:browser");
win.open(addonData, "", "");

It would be great if someone could create an add-on out of this, to display the add-on sizes in Firefox more comfortably. (thanks Jojo for the tip)

The option to clear the recent history has been included in Firefox for quite some time, but many Firefox users do not know that this option exists. The Clear Recent History menu becomes available after pressing Ctrl-Shift-Del, or following the Tools > Clear Recent History Path.

The new menu window that opens up displays all kinds of data that can be deleted, and a time range at the top that is often overlooked as it displays Everything by default.

clear recent history

A click on the pull down menu however reveals time ranges that can be selected, for instance the last hour, two hours or four hours.

To pick a harmless example. Say you have decided to shop for a birthday present for a household member. Instead of using the private browsing mode you could simply use the browser as normal, and open the Clear Recent History menu afterwards to delete all data that has been accumulated in the last x hours so that it becomes impossible to retrace the last browsing session.

In Firefox 3.6 however only new tabs are opened at the far right of the tabbar while new tabs that are opened from existing tabs, e.g. by middle-clicking a link in an already open tab, are opened next to the tab containing the link.

That feels like inconsistent behavior to some Firefox users. Those who prefer the old way of opening new tabs (all at the right end) can make Firefox 3.6 change that behavior to the default behavior of previous Firefox versions.

The changes are made in the about:config configuration window. Simply enter about:config in the Firefox address bar to open the configuration menu. You might need to get past a warning message if that is the first time you open that menu.

Now filter for the term tabs.insertRelatedAfterCurrent. The default value of the parameter is true which simply means that related tabs are opened after the current and not at the end. A double-click on the row will change the value to false indicating that related tabs will from then on be opened at the end of the tabbar just like new tabs.

The Firefox add-on Greasefire changes this to the better. It integrates itself nicely with the Greasemonkey extension and becomes active on every website for which Greasemonkey scripts are available. The extension maintains a list that gets regularly updated so that new and updated Greasemonkey scripts will be listed when the user takes a look at them

All available Greasemonkey scripts for that specific website will be displayed in a new window that opens when the user right-clicks on the icon in the Firefox status bar and selects the line telling him how many Greasemonkey scripts are available for it.

The manager can then be used to discover the various scripts to find out what they are doing. It is also possible to install them right away or take a look at the source code first to make sure they are not malicious.

Greasefire provides an easy and elegant method of discovering and installing new Greasemonkey scripts in Firefox. Should be definitely worth a test for users who use Greasmonkey or want to start doing so.

What you need to do is add the mobile version of Google Calendar to your bookmarks, right-click the bookmark, select properties from the menu and check the “Load this bookmark in the sidebar” option.

Whenever you load the bookmark from then on it will be displayed in the sidebar displaying the current and upcoming events. This is great if you look at your entries frequently.

Read More:

Google Calendar Mobile
via Firefox Facts