Options/Preferences Window

This document explains all options available in the Options window of Firefox.

General Options

General Options Panel

Home Page

Here you are able to specify the page (or tab group) that Firefox will show when you launch it or press the Home button. Enter the address in the Location's) field.

Click Use Current Page(s) to use the page you're currently visiting. You can also use multiple home pages. If more than one browser tab is currently opened, this button will set the whole tab group as a start page.

To specify the home page(s) using a bookmark, click Use Bookmark.... You can even select a whole bookmark folder to be used!

If you don't want a home page to be loaded, click Use Blank Page.

Fonts & Colors

Click the Fonts & Colors... button to change the default fonts and colors used by Firefox.

Fonts for:

Normally, web pages are displayed in the default font set by your browser or in a font chosen by the web pages' authors.

To change the default fonts:

From the Fonts for drop-down list, choose a character set. For instance, to set default fonts for the Western (Roman) character set, choose Western.
Select whether proportional text should be serif (like "Times New Roman") or sans-serif (like "Arial"). Then specify the font size you want for proportional text.
Specify the font to use for Serif, Sans-serif and Monospace fonts. You can also change the size for Monospace fonts.

You can also specify the display resolution, which is normally 96 dpi. Note that if you select Other... in the drop-down list of resolutions, you will see a tiny and unusable dialog. This is a known bug in Firefox.

Finally, you can set the minimum font size to be used on screen. This can be useful on some sites that use very small fonts that are barely readable.

Text and Background

Here you can change the default text and background color to be used on Web pages that haven't specified that information. Click on the color samples to select colors.

Use system colors

Check this option to use the colors defined in your OS settings instead of the colors specified above.

Link Colors

Here you can change the default colors for Web links. Click on the color samples to select colors.

Underline links

By default, links are underlined on Web pages. Uncheck this option to disable this. Note that many sites specify their own styling rules (including this site) and this option has no effect on those sites.

Always use my:

Fonts

By default, Firefox uses the fonts specified by the Web page author. Enabling this option will force all sites to be using your default fonts instead.

Colors

By default, Firefox uses the colors specified by the Web page author. Enabling this option will force all sites to be using your default colors instead.

Languages

Some web pages are offered in more than one language. Click the Languages button to specify your preferred languages.

Language selection: To add a language, press Select a language to add..., choose the language, and click the Add button. Remove a language by selecting it in the list of active languages and clicking the Remove button.
You can reorder languages to determine the preferred one in case a page is provided in two or more of your selected languages. Do this using the Move Up and Move Down buttons.

Character Encoding: The character encoding selected here will be used to display pages that do not specify which encoding to use.

Default Browser

On Windows, you can set Firefox as the default browser by clicking Set Default Browser. This will ensure Firefox is used whenever an application is trying to display a web page or when you double-click a HTML file. This feature does not work in Linux or Macintosh.

Connection Settings

Many organizations block access from the Internet to their networks. This prevents outside parties from gaining access to sensitive information. The protection is called a firewall.

If your organization has a firewall, the browser may need to go through a proxy server before connecting you to the Internet. The proxy server prevents outsiders from breaking into your organization's private network.

Configure Proxies to Access the Internet

Direct connection to the Internet

This is the default option. Choose this if you don't want to use a proxy.

Manual proxy configuration

Choose this if you don't have a proxy location (URL). Ask your system administrator for the names and port numbers of the servers running proxy software for each network service and enter the information in the appropriate fields.

Automatic proxy configuration URL:

If there's a proxy configuration file at your workplace, ask the system administrator for its URL and enter it here. Press Reload to load the settings.

Privacy Options

Privacy Options Panel

The Privacy panel contains options related to your privacy. As you browse the web, information on where you have been, what pages you have visited, etc are stored here. You can click the Clear button on each section to clear that information. Alternatively you can clear all information stored while browsing by clicking Clear All. A confirmation dialog will be shown before clearing the information.

To display section-specific options, expand the view by clicking on the small + buttons. In the image above, the History section is expanded.

History: Here you can specify for how many days you want the browser to remember what pages you have visited. The default is 9 days.

Saved Form Information: Save information I enter in web page forms and the Search bar

When you enter information in web forms, Firefox remembers what you type and automatically makes suggestions when you enter information again. To stop this behaviour, uncheck this option.

Saved Passwords: Remember Passwords

Firefox is capable of securely storing passwords you enter in web forms to make it easier to log on to Web sites. You can manage the saved passwords and delete individual passwords by clicking View Saved Passwords. To stop saving passwords altogether, uncheck this option.

Download Manager History: The Download Manager (accessible from the Tools menu or by pressing Ctrl+Y) stores shortcuts to your recent downloads. Use the Clear button to clear the download history. You can also enable automatic removal from the Download Manager after each download, or when exiting Firefox. More Download options are available in the Downloads panel.

Cookies

A cookie is a file created by a web site that stores information on your computer, such as your preferences when visiting that site. For example, this site stores the navigation menu behaviour (locked or unlocked) in a cookie file.

To display the stored cookies, click View Cookies. Click the Exceptions button to allow or deny specific sites to store cookies on your computer, regardless of the global settings.

Allow sites to set cookies

By default, cookies are enabled. Uncheck this option to disable the use of cookies. Note that some sites may not work properly when this feature is disabled.

for the originating Web site only

Selecting this option will restrict cookie usage to the originating Web site only, meaning that no foreign cookies will be stored.

You have three options of for how long Firefox should store cookies, as explained below:

until they expire
This is the default option. Cookies will be stored for as long as the site specifies.
until I close Firefox
This will remove cookies when you close the browser.
ask me every time
Select this option to gain maximum control of which cookies are allowed to be stored on your computer. A confirmation dialog will be displayed each time a site tries to save a cookie.

Cache: Pages you view are normally stored in a special cache folder for quicker viewing the next time you visit the same page. Here you are able specify the amount of disk space the cache can use.
In addition to specifying the amount of disk space, you can also specify the cache folder and the memory usage.

Web Features Options

Web Features Options Panel

Block Popup Windows

By default, Firefox blocks annoying popup windows on Web sites. Unchecking this option will disable popup blocking.

Some sites make legitimate use of popup windows. Therefore, the popup blocking feature has a simple whitelist mechanism to allow certain sites to open popups anyway. To add a site to the whitelist, click Allowed Sites and enter the address of the web site and click Allow.

To remove a site from the whitelist, select that site from the list and then click Remove Site. To clear the whitelist completely, click Remove All Sites.

Allow web sites to install software

By default, Firefox allows some specific web sites to install extensions and add-ons for Firefox. To view and edit this list of allowed sites, click Allowed Sites. This whitelist mechanism works the same way as the Block Popup Windows feature explained above.

Load Images

By default, images are loaded on Web pages. Uncheck this option to disable images completely. If images are loaded, you can still specify not to load images from certain sites by clicking Exceptions.

for the originating Web site only

Enabling this option will make sure that only images located at the current Web site are loaded.

The Exceptions window lists all servers that you are currently blocking images for. To block a server, such as an advertising server, right click on an image on a Web page and select Block Images from <server>. To unblock a site, select that server from the Exceptions window and click Remove Site. To unblock all sites so all images are shown again, click Remove All Sites.

Enable Java

Java is a popular programming language for the web developed by Sun Microsystems. A single Java program can run on many different kinds of computers, thus avoiding the need for programmers to create a separate version of each program for each kind of computer. Uncheck this option to disable Java applets in Firefox. Note that in order for Java applets to work, you must install the Java plug-in.

Enable JavaScript

JavaScript is a scripting language commonly used to construct web pages. Programmers use JavaScript to make web pages more interactive; for example, to display forms and buttons. Disabling JavaScript may cause some sites not to work properly, including this one.

While it is usually recommended to keep JavaScript enabled, there are some functions that you may want to disable. Click the Advanced... button to display these options.

Allow scripts to:

Move or resize existing windows

Uncheck this option to disable moving and resizing windows using scripts.

Raise or lower windows

Uncheck this option to make sure scripts cannot raise or lower windows.

Disable or replace context menus

Uncheck this option to prevent web pages from disabling or changing the Firefox context menu.

Hide the status bar

Uncheck this option to force the status bar to be displayed in popup windows.

Change status bar text

Uncheck this option to disable annoying status bar text scrolling and Web address hiding.

Change images

Uncheck this option to disable changing of images. Disabling this can make some menus a bit harder to navigate.

The options displayed here are certainly not all of them. You can also make sure all popup windows are resizable, minimizable, and that the menu and toolbar is always displayed. All of these options are available on the Tips & Tricks page.

Downloads Options

Downloads Options Panel

This panel controls how Firefox handles different file types such as applications, compressed files, multimedia, etc.

Download Folder

Ask me where to save every file

Firefox will ask you where you want a file to be saved when you download something.

Save all files to this folder:

This is the default option. It allows you to specify a default folder where all downloads will be saved to, such as the My Downloads folder. You can browse to a specific folder by selecting Other... from the drop-down list of available folders. To show the folder, click the Show Folder button, which will open the folder in the default file manager (e.g. Windows Explorer or Nautilus).

File Types

This list contains file types that you have downloaded. You can choose what Firefox should do when clicking on a specific file type. Select the file type you want to modify and click the Change Action... button.

This will display the Change Action window, where you can choose to have the file type being opened by an application or saved to disk. For example, if you view lots of media files on Web pages, you might want to specify that it always open it in your media player, instead of asking where you want the file to be saved.

Open them in the Default application:

Select this option to open this file type in the default application for that file type (determined by the Operating System).

Open them in this application:

Select this option to specify another application that should handle this file type. You will see a dialog asking you to specify the application to use. If not, click the Change... button.

Save to Disk

This option will save the files to disk. If you have the Save all files to this folder option selected, the files will be saved automatically.

To remove an automatic rule for a file type, select that file type and click the Remove button.

From the Downloads panel, you can also control the plug-ins for Firefox. Click the Plug-Ins... button to display the Plug-Ins window:

From this window, you can control which plug-ins for Firefox that are allowed to run. For example, if you don't like Flash animations in general, but still find a need to have the plug-in installed, you can disable the plug-in here (as shown in the screenshot), which will block any Flash ads and animations until you enable the plug-in again.

Advanced Options

Advanced Options Panel

The advanced panel contains many options that are less likely to be used by most people, but still useful and sometimes critical options for some people.

Accessibility

Move system caret with focus/selection changes

Specifies whether to move the system caret whenever the focus or selection changes. Some accessibility aids, such as screen readers or screen magnifiers, use the system caret to determine which area of the screen to read or magnify.

Use Find As You Type

Find As You Type is a very useful feature in Firefox. It is a fast way of finding links or text in a Web page without the need of displaying complex search dialogs. Read more about Find As You Type at mozilla.org.

There are more options for Find As You Type covered in the Tips & Tricks page.

Browsing

Resize large images to fit in the browser window

This feature is similar to the one seen in Internet Explorer. It makes images that are larger than can be fit on the screen shrink automatically so you can view the whole picture. Click on the image to view its full size.

Use autoscrolling

Autoscrolling is a useful feature which allows you to scroll the page by just holding down the middle mouse button (usually the scroll wheel) and move the mouse up or down. Some people find this annoying so here's the option for it.

Use smooth scrolling

Smooth scrolling is still somewhat experimental in Firefox, but it can be very useful if you read a lot of long pages. Normally, when you press the Page Down key, the view jumps directly down one page. With Smooth Scrolling, it slides down more smoothly, so you are actually able to see how much it scrolls. This makes it easier to resume reading from the point you were before.

Tabbed Browsing

Open links from other applications in:

a new window

With this option selected, any web pages opened by other applications will be displayed in a new window.

a new tab in the most recent window

With this option selected, any web pages opened by other applications will be displayed in a new browser tab.

the most recent tab/window

This is the default option. Any web pages opened by other applications will be displayed in the current tab/window.

Hide the tab bar when only one website is open

If you're only viewing one Web page in a browser window, the tab bar is not shown. Uncheck this option to show the tab bar all the time.

Select new tabs opened from links

When you middle-click on Web links (or hold down Ctrl while clicking with the left mouse button), the links will be opened in a new tab. That tab will not be shown directly; it will be loaded in a background tab. Check this option to load the link in a foreground tab instead, which will show that tab directly.

Select new tabs opened from bookmarks or history

Same as the option above, but this one is for middle-clicking on bookmark or history links.

Warn when closing multiple tabs

If you're trying to close a window with more than one tabs opened, Firefox will display a confirmation dialog before the window is closed, to prevent accidental data loss.

Software Update

Firefox can check whether a new version of your installed extensions or of Firefox itself is available.

Firefox

By default, Firefox will periodically check and notify you when a new version is available. Uncheck this option to disable the periodic check.

My Extensions and Themes

By default, Firefox will periodically check and notify you when a new version for one of your installed extensions or themes is available. Uncheck this option to disable the periodic check.

Click the Check Now button to manually perform a check for updates to Firefox and installed extensions.

Security

Use SSL 2.0

Specifies whether you want to send and receive secured information through SSL2 (Secured Sockets Layer Level 2), the standard protocol for secure transmissions. All secure Web sites support this protocol.

Use SSL 3.0

Specifies whether you want to send and receive secured information through SSL3 (Secured Sockets Layer Level 3), a protocol that is intended to be more secure than SSL2. Note that some Web sites might not support this protocol.

Use TLS 1.0

Specifies whether you want to send and receive secured information through TLS (Transport Layer Security), an open security standard similar to SSL3 (Secure Sockets Layer). Note that some Web sites might not support this protocol.

Certificates

Certificates help perform encryption and decryption of connections to secure sites.

Client Certificate Selection: When a web site requests a secure connection, Firefox will by default automatically use an appropriate certificate. If you wish to manually choose a certificate (for example, if you wish to use a certain type of encryption instead of what is automatically selected), select the option preference "Ask Every Time" and you'll be in complete control of what certificates you use while browsing.

Manage Certificates: Click the Manage Certificates... button to view stored certificates, import new certificates, and back up or delete old certificates in Firefox.

Manage Security Devices: Security devices can encrypt and decrypt connections and store certificates and passwords. If you need to use a security device other than the one in Firefox, click the Manage Security Devices... button.

Validation

Validation ensures that certificates used by Firefox are not obsolete.

CRL: Firefox can use CRLs (also known as Certificate Revocation Lists) to ensure that your certificates are not invalid. If you need to add a CRL to Firefox or wish to view information about CRLs you have installed, click the Manage CRLs... button.

OCSP: OCSP (Online Certificate Status Protocol) is a way to validate your certificates every time they are viewed or used. Firefox does not use OCSP by default, but if you want to enable it, you can do so here. You will most likely only need to change this if your Internet environment requires it.