Hidden Mozilla/Firefox/Thunderbird Prefs

The following is a list of hidden Mozilla prefs I know of that can be quite helpful. Don't know how to change prefs? See this link.

There are some interesting things you can do with userChrome.css and userContent.css files. Take a look - userChrome.css  userContent.css

Know a pref that might be a useful addition? Something over here is wrong or doesn't work? Then email me! and let me know.

Browser/Firefox MailNews/Thunderbird AddressBook LDAP Editor


// Don't close window when last tab is closed (adds a close button to last tab).
// See bug 455852.

user_pref("browser.tabs.closeWindowWithLastTab", false);

// Enable HTTP Pipelining. This can improve performance but
// may also cause issues. See bug 264354.

user_pref("network.http.pipelining", true);

// If you hate tabs and don't want middle-click to open a link in
// a new tab, set this pref to false.

user_pref("browser.tabs.opentabfor.middleclick", false);

// Turn off domain guessing (which adds www. and .com) for link URLs
// This means that if you type http://cnn/, Mozilla will not try
// to go to http://www.cnn.com. For more details read bug 34943

user_pref("browser.fixup.alternate.enabled", false);

// Get rid of the Print Progress dialog that pops up when printing.
// This is not necessarily a good idea, but can be useful.

user_pref("print.show_print_progress", false);

// This pref displays the alt-text instead of the "image-not-found" image
// true = force ALT text for missing images to be layed out inline

user_pref("browser.display.force_inline_alttext", false);

// To set the user-agent string to whatever you desire. Following are a
// few examples. Although you can do this, I would recommend using
// something like a user agent switcher

user_pref("general.useragent.override", "Mozilla/5.0 (X11; U; Linux i686; en-US; rv 0.9.2) Gecko/20010726 Netscape6/6.1");
user_pref("general.useragent.override", "Mozilla/5.0 (compatible; MSIE5.5; Windows 98;");
user_pref("general.useragent.override", "Mozilla/4.0 (compatible;)");

// If you want Mozilla to open up a mail client other than Mail/News
// when you click on a mailto: URL, add this pref.

user_pref("network.protocol-handler.external.mailto", true);
// similarly for external news app

user_pref("network.protocol-handler.external.news", true);

// For security reasons, Mozilla does not allow connections to
// certain ports. To override this on a per-port basis, add a comma-separated
// list of ports to default/all.js (in your mozilla installation directory).
// For example, to unblock ports 1, 3, and 7, set the following pref:

pref("network.security.ports.banned.override", "1,3,7");
// Key modifier stuff: see bug 22515

// Motif-style access keys:
user_pref("ui.key.accelKey", 18);
user_pref("ui.key.menuAccessKey", 0);

// Windows-style access keys:

user_pref("ui.key.accelKey", 17);
user_pref("ui.key.menuAccessKey", 18);
user_pref("ui.key.menuAccessKeyFocuses", true);

// Turn off Unix-style autocopy
// (or set it to true to turn it on on non-Unix platforms):


// Middle mouse prefs: true by default on Unix, false on other platforms.

user_pref("middlemouse.scrollbarPosition", false);

// See bug 93827 for details. The functionality of "print.print_method"
// prefs is the following on Unix
// 0 - autoselection of print module based on existence of $XPSERVERLIST env var
//     this is now the default - see unix.js)
// 1 - use Xprint module
// 2 - use PostScript module
// 3 - "reserved" value, not implemented on Unix :-)

user_pref("print.print_method", 0)

// The following pref will disable selecting the entire URL when you
// click in the URL bar. The default is true. (double clicking on the
// URL will still select the entire URL for you).

user_pref("browser.urlbar.clickSelectsAll", false);


// Add this pref if you don't like abbreviated newsgroup names.

user_pref("mail.server.default.abbreviate", false);

// This pref controls the "Advance to next unread message in <x> folder" behaviour
// 0 - Always go to the next folder without prompting
// 1 - Ask before going (default behaviour)
// 2 - Don't prompt and don't go to the next folder with unread messages

user_pref("mailnews.nav_crosses_folders", 0);

// In order to prevent stress on news servers, Mozilla collapses
// news servers by default at startup so that it doesn't check for
// new messages. You can enable the persistance of newsgroups by
// adding the following pref. Related thread on n.p.m.mail-news

user_pref("news.persist_server_open_state_in_folderpane", true);

// To speed up message compose window
// See Ducarroz's post

user_pref("mail.compose.max_recycled_windows", 1);

// Show the user agent of incoming messages

user_pref("mailnews.headers.showUserAgent", true);

// To get rid of the sending window

user_pref("mailnews.show_send_progress", false);

// Change the reply header
// 0 - No Reply-Text
// 1 - <Author> wrote:   - Netscape 3.xx/4.xx style
// 2 - On <date> <author> wrote:
// 3 - user-defined string. Use the prefs below in conjuction with this.

user_pref("mailnews.reply_header_type", 2);
// If you set 3 for the pref above then you may set the following prefs.
// The end result will be <authorwrote><separator><ondate><colon>

user_pref("mailnews.reply_header_authorwrote", "%s said the following");
user_pref("mailnews.reply_header_ondate", "on %s");
user_pref("mailnews.reply_header_separator", " ");
user_pref("mailnews.reply_header_colon", ":");

// This should change attached image and text files from inline to attachment.

user_pref("mail.content_disposition_type", 1);

// To change the color of the quote bar
// Replace #0000A0 with the colour of your choice.

user_pref("mail.citation_color", "#0000A0");

// Turn off graphical reply style in the message window

user_pref("mail.quoted_graphical", false);

// display glyph, see http://www.bucksch.org/1/projects/mozilla/16507
pref("mail.display_glyph", true);

// use HTML-style quoting for quoting plain text (during HTML replies)
pref("mail.quoteasblock", true);

// Format=flowed prefs, RFC 2646
pref("mailnews.send_plaintext_flowed", true);
user_pref("mailnews.display.disable_format_flowed_support", true);
pref("mail.display_struct", true);
pref("mail.send_struct", false);

// This option tells Mozilla to check for IMAP folders other than INBOX
// Currently Mozilla just checks INBOX for new mails.

user_pref("mail.check_all_imap_folders_for_new", true);


// Use this pref to get rid of the "Get Map" button in the address book.
// See this link for more details. (Thanks for the link, Paul)

user_pref("mail.addr_book.mapit_url.format", "");

LDAP preferences

// For a more complete description of LDAP and its associated prefs look at
// http://mozdev.org/ftp/pub/sun/SummaryPatchII.txt

// In order to activate the Mozilla integration with OutLook, it is
// necessary to manually edit the preferences,file, called prefs.js.
// This file is located in the mozilla user's directory.
// 4 entries must be added to this file to support MAPI/OutLook integration:

user_pref("ldap_2.servers.mapitest.description", "mapitest");
user_pref("ldap_2.servers.mapitest.dirType", 3);
user_pref("ldap_2.servers.mapitest.position", x);
user_pref("ldap_2.servers.mapitest.uri", "moz-aboutlookdirectory://");

// Added LDAP support in the Mozilla Address Book
// 4 entries must be added to this file to support LDAP integration:

user_pref("ldap_2.servers.myldap.description", "myldap");
user_pref("ldap_2.servers.myldap.dirType", 777);
user_pref("ldap_2.servers.myldap.position", x);
user_pref("ldap_2.servers.myldap.uri", "moz-abldapdirectory://ldap1.holland/dc=sun,dc=com?(or(DisplayName,bw,paul)(PrimaryEmail,bw,paul))");


// Newline paste behavior:
// 0 = paste unchanged,
// 1 = paste only first line,
// 2 = replace with spaces,
// 3 = strip newlines

user_pref("editor.singleLine.pasteNewlines", 0);

Maintained by Pratik Solanki. email: pratik.solanki@gmail.com