About:config entries
about:config is a list of preferences that you can change. This article is meant to be a partial documentation of those preferences. Alternative lists can be found here [1], here [2] and here [3].
See also: Editing configuration and User.js file.
Many of the entries that appear in Firefox will also apply to Mozilla and vice versa.
Note: Spaces between the dots in preference names exist purely for word-wrapping. They are actually not present and should not be thought as so. Editors of this page must take follow this convention in order to not force users to horizontally scroll this article.
Accessibility.*
Name | Type | Meaning of Values |
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accessibility. accesskeycausesactivation | Boolean | True (default): Using an accesskey will have the same effect as clicking on the applicable element with the mouse. False: Using an accesskey will only focus the applicable element. |
accessibility. browsewithcaret | Boolean | True: A caret is present in the browser window to use to select text with the keyboard. False (default): No caret is present. This can be toggled using the [F7] key.
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accessibility. tabfocus | Integer | Determines which web page elements can gain focus when [Tab] key is pressed.1: Text field form controls only 2: All form controls except text fields 3: All form controls 4: Hyperlinks and hyperlinked images 7 (default): All form controls and hyperlinks |
accessibility. typeaheadfind | Boolean | True: Activates Find As You Type. False (default): Disables Find As You Type. Note: In Firefox, this can be changed via "Tools → Options → Advanced → Accessibility → Begin finding when you begin typing" |
accessibility. typeaheadfind. autostart | Boolean | True (default): Find As You Type will start automatically when typing starts and a form control like a text area or text box does not have focus. False: Find As You Type will only start when / is pressed for any word and when ' is pressed for link searching.
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accessibility. typeaheadfind. enablesound | Boolean | True (default): Find As You Type will play a sound when the typed in search phrase is not found. False: Find As You Type will not play any sounds. |
accessibility. typeaheadfind. enabletimeout | Boolean | True (default): Find As You Type will end after a set time if no keys are pressed. False: Find As You Type will not end due to a timeout. To end a search use the escape key. |
accessibility. typeaheadfind. flashBar | Integer | 0: Don't flash the Find Toolbar when a result is found 1: Flash the Find Toolbar's search field when a result is found Note: As of Firefox 1.0, this feature is sketchy at best and nonfunctional at worst. |
accessibility. typeaheadfind. linksonly | Boolean | True: Find As You Type will only search links. False (default): Find As You Type will search all the text. |
accessibility. typeaheadfind. soundURL | String | The sound to play when Find As You Type does not find a match. (filename): .wav file to play for the error sounddefault (default): The default sound beep: System beep |
accessibility. typeaheadfind. startlinksonly | Boolean | True: When finding links, the search will only match links from the beginning of the link's text. False (default): The search will match any part of a link's text. |
accessibility. typeaheadfind. timeout | Integer | The number of milliseconds that Find As You Type will wait between key presses before ending an active search. Default value is 5000. |
accessibility. usebrailledisplay | String | Specifies the Braille display module to use. Default value is an empty string. Note: Currently unused. Planned for future use. |
accessibility. usetexttospeech | String | Specifies the text-to-speech module to use with the browser (e.g. "ViaVoice"). Default value is an empty string. Note: Currently broken. |
accessibility. warn_on_browsewithcaret | Boolean | True (default): You will be promted to comfirm enabling caret browsing. False: The opposite of above. |
Advanced.*
Name | Type | Meaning of Values |
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advanced. always_load_images | Boolean | Unused. Holdover from Netscape 4.x (then general.always_load_images). Default value is true. |
advanced. mailftp | Boolean | True: Use a specified email address (the value in network.ftp.anonymous_password) as the password for anonymous FTP servers False (default): Send default "mozilla@example.com" for password |
advanced. system. supportDDEExec | Boolean | Previously used (before Firefox 0.9) to open links from external sources as tabs in a single window. Currently deprecated in favor of preferences under "Tools → Options → Advanced → Tabbed Browsing". Default value is true. |
Alerts.*
Note: These apply to the "Downloads Complete"- and "Updates Available"-style alerts, not regular Javascript alert()
dialogs.
Name | Type | Meaning of Values |
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alerts. height | Integer | Height in pixels of the alert box. Default value is 50. |
alerts. slideIncrement | Integer | How many pixels to move per step when "sliding". Default value is '1. |
alerts. slideIncrementTime | Integer | How many milliseconds per step of "slide" movement. Default value is 10. |
alerts. totalOpenTime | Integer | How many milliseconds to show the alert. Default value is 4000. |
App.*
Name | Type | Meaning of Values |
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app. build_id | String | Date of build in YYYYMMDD format |
app. extensions. version | String | Browser version given to extensions to check for compatibility |
app. id | String | The GUID corresponding to the program. Default value for Firefox is {ec8030f7-c20a-464f-9b0e-13a3a9e97384} .
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app. update. autoUpdateEnabled | Boolean | True (default): Periodically check update.mozilla.org in the background for updates to the browser False: Disable all checks for browser updates Note: In Firefox, this can be changed via "Tools → Options → Advanced → Software Update → Periodically check for updates to Firefox" |
app. update. enabled | Boolean | True (default): Allow updates to the browser False: Disable browser updates Note: Probably deprecated in favor of app.update.autoUpdateEnabled |
app. update. interval | Integer | Number of seconds between checks for updates. Default value is 86400000 (1000 days). |
app. update. lastUpdateDate | Integer | Time of last update in UNIX epoch format (seconds since 1970-01-01) |
app. update. performed | Boolean | True: Browser updates have been installed False (default): No browser update has been performed |
app. update. updatesAvailable | Boolean | True: The update manager has found updates False (default): There are no updates to download or install |
app. update. url | String | URL for browser update notification. Default value is https://update.mozilla.org/update/firefox/en-US.rdf. |
app. version | String | Version number |
Bidi.*
Name | Type | Meaning of Values |
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bidi. browser. ui | Boolean | True: Allows the browser interface to use a bi-directional language set False (false): Opposite of the above |
bidi. characterset | Integer | How the browser determines the character set to use 1 (default): Document-specified character set 2: Default character set |
bidi. controlstextmode | Integer | How controls are used 1 (default): Logical 2: Visual 3: Container |
bidi. direction | Integer | Select direction of text 1 (default): Left-to-right 2: Right-to-left |
bidi. numeral | Integer | How numerals are displayed 0 (default): Nominal numerals 1: Regular context numerals 2: Hindi context numerals 3: Arabic numerals 4: Hindi numerals |
bidi. support | Integer | Select provider of bi-directional support 1 (default): Mozilla 2: OS 3: Disable |
bidi. texttype | Integer | Type of text 1 (default): Charset 2: Logical 3: Visual |
Browser.*
Name | Type | Meaning of Values |
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browser. active_color | String | The default color for active links as a hex code. Default is #EE0000 .
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browser. anchor_color | String | The default color for links as a hex code. Default is #0000EE Note: In Firefox, this can be changed via "Tools → Options → General → Fonts & Colors → Unvisited Links". |
browser. blink_allowed | Boolean | True (default): Use of the blink tag or CSS's text-decoration: blink will result in blinking elements.False: Blinking is disabled. |
browser. block. target_new_window | Boolean | True: Links with target set to _blank will open in the current tab instead of a new window.False: Links with target set to _blank will open in a new window.
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browser. bookmarks. file | String | The full path and filename of your bookmarks file (bookmarks.html ). In Windows, the path separator must be two slashes (e.g. "C:\\Path\\To\\bookmarks.html ")
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browser. bookmarks. import_system_favorites | Boolean | Determine the system bookmark strategy. True: Enable a "live view" of system bookmarks which is read-only False (default): Opposite of above. Note: Setting this to "true" will prevent "Imported IE Favorites" folder from being deleted where applicable. See Bug 22642. |
browser. bookmarks. livemark_refresh_seconds | Integer | The number of seconds between Live Bookmark checks. Values under 60 are assumed to be 60; the default is 3600 (1 hour). |
browser. bookmarks. sort. direction | String | The order in which to sort bookmarks in the Bookmarks Manager descending (default): Unsorted natural: Alphabetically, A-Z ascending: Alphabetically, Z-A Note: In Firefox, this can be changed via "Bookmarks → Manage Bookmarks... → View" |
browser. bookmarks. sort. resource | String | The RDF source to use when sorting the bookmarks in the Bookmarks Manager rdf:http://home.netscape.com/NC-rdf#Name (default): by bookmark name rdf:http://home.netscape.com/NC-rdf#URL: by URL rdf:http://home.netscape.com/NC-rdf#ShortcutURL: by bookmark keyword rdf:http://home.netscape.com/NC-rdf#Description: by description rdf:http://home.netscape.com/NC-rdf#BookmarkAddDate: by bookmark creation date rdf:http://home.netscape.com/WEB-rdf#LastModifiedDate: by bookmark modification date rdf:http://home.netscape.com/WEB-rdf#LastVisitDate: by date of last visit Note: In Firefox, this can be changed via "Bookmarks → Manage Bookmarks... → View" |
browser. cache. check_doc_frequency | Integer | How often to check the remote page for a newer version than what might be in the cache 0: Check once per browser session 1: Check every time I view the page 2: Never check (always use cached page) 3 (default): Check when the page is out of date (automatically determined) |
browser. cache. disk. capacity | Integer | Amount of disk space allowed for the browser's cache (in KB). Default is 50000. Note: In Firefox, this can be changed via "Tools → Options → Privacy → Cache" |
browser. cache. disk. enable | Boolean | True (default): Use disk cache, up to capacity specified in browser.cache.disk.capacity False: Disable disk cache (same effect as setting browser.cache.disk.capacity to 0) |
browser. cache. disk. parent_directory | String | Full path to the directory used for storing the browser's cache. In Windows, the path separator must be two slashes (e.g. "C:\\Path\\To\\Cache ")
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browser. cache. disk_cache_ssl | Boolean | True: Cache content received via SSL (security risk!) False (default): Do not cache content received via SSL Note: More information in Bug 205921 |
browser. cache. memory. capacity | Integer | Determines how the browser uses RAM for cache. -1 (default): Automatically set size of capacity as a percentage of physicall RAM 0: disables the memory cache device entirely (n): Set the maximum RAM used to n KB. |
browser. cache. memory. enable | Boolean | True (default): Use memory cache, up to capacity specified in browser.cache.memory.capacity (if set); otherwise, use a percentage of physical RAM (See Bug 105344) False: Disable memory cache (same effect as setting browser.cache.memory.capacity to 0) |
browser. chrome. favicons --OR-- browser. chrome. site_icons |
Boolean | True (default): favicons/site icons will be visible, cached, etc. False: favicons/site icons will be not visibile, cached, etc. |
browser. chrome. toolbar_style | Integer | Set toolbar style for browser 0: Pictures Only 1: Text Only 2 (default): Pictures and Text |
browser. chrome. toolbar_tips | Boolean | Determines tooltip behavior for chrome elements. True (default): Show tooltips for toolbars and bookmarks. Display the name and URL for bookmarks False: Hide tooltips for chrome elements |
browser. chromeURL | String | Location of browser's UI chrome; launched at browser startup. Default value is chrome://browser/content/ |
browser. display. background_color | String | The default color for the background of browser content as a hex code. This affects blank tabs, web pages whose backgrounds are not explicity set, and XUL error pages. Default value is #FFFFFF .Note: In Firefox, this can be changed via "Tools → Options → General → Fonts & Colors" |
browser. display. focus_background_color | String | The default color for the background of focused elements as a hex code. Default value is #117722 . Requires that browser.display.use_focus_colors be true
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browser. display. focus_ring_on_anything | Boolean | True: Display the focus ring (normally only shown on links) on anything False (default): Display the focus ring on links only |
browser. display. focus_ring_width | Integer | Determines the display of the focus ring around focused elements. 0: Hide focus ring 1 (default): Dots around focused elements will be displayed with a 1 pixel border (n): Display dots with a width of n pixels around focused elements |
browser. display. focus_text_color | String | The default color for the text of focused elements as a hex code. Default value is #ffffff . Requires that browser.display.use_focus_colors be true
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browser. display. force_inline_alttext | Boolean | True: Force broken images' alt text to be displayed inlineFalse (default): Opposite of above Note: This appears to happen in Firefox regardless of this setting |
browser. display. foreground_color | String | The default color for the foreground of browser content as a hex code. This affects web pages whose text colors are not explicity set and XUL error pages. Default value is #000000 .Note: In Firefox, this can be changed via "Tools → Options → General → Fonts & Colors" |
browser. display. normal_lineheight_calc_control | Integer | Determine method of calculating line-height (leading) in layout -1: Uninitialized 0: Don't include external leading 1: Use what the font vendor provides 2 (default): Compensate leading if vendor's leading is insufficient |
browser. display. screen_resolution | Integer | DPI of display device. Affects CSS absolute length units (e.g. pt, mm). -1: Unable to determine the resolution (assume preference is not set) 0: Force use of operating system's logical resolution (n): Assume screen DPI of n. Default value is 96. Note: In Firefox, this can be changed via "Tools → Options → General → Fonts & Colors → Display Resolution" |
browser. display. show_image_placeholders | Boolean | True (default): Show placeholders while image is loading False: Opposite of above |
browser. display. use_document_colors | Boolean | True (default): Allow documents to specify colors to use False: Opposite of above Note: In Firefox, this can be changed via "Tools → Options → General → Fonts & Colors → Always use my colors" |
browser. display. use_document_fonts | Integer | 0: Never use document's fonts 1: Allow documents to specify fonts to use 2: Always use document's fonts (deprecated) Note: In Firefox, this can be changed (between 0 and 1) via "Tools → Options → General → Fonts & Colors → Always use my fonts" |
browser. display. use_focus_colors | Boolean | True: Set colors on focused items according to preferences False (default): Do not set colors on focused items |
browser. display. use_system_colors | Boolean | True: Use colors specified by OS to display documents False (default): Opposite of above Note: In Firefox, this can be changed via "Tools → Options → General → Fonts & Colors → Use system colors" |
browser. dom. window. dump. enabled | Boolean | True: Enable Javascript dump() outputFalse: Opposite of the above |
browser. download. dir | String | The last directory used for saving a file from the "What should (browser) do with this file?" dialog. |
browser. download. folderList | Integer | Which of several internally-specified locations to use for the default download directory 0 (default): the desktop 1: the downloads folder 2: the last folder specified for a download Note: In Firefox, this can be changed via "Tools → Options → Downloads → Download Folder → Save all files to this folder" |
browser. download. lastDir | String | Path to the last directory used for a download via "Save As." |
browser. download. manager. alertOnEXEOpen | Boolean | True (default): warn the user attempting to open an executable from the Download Manager False: display no warning and allow executable to be run Note: In Firefox, this can be changed by checking the "Don't ask me this again" box when you encounter the alert. |
browser. download. manager. closeWhenDone | Boolean | True: Close the Download Manager when all downloads are complete False (default): Opposite of the above Note: In Firefox, this can be changed via "Tools → Options → Downloads → Download Manager → Close the Download Manager when all downloads are complete" |
browser. download. manager. flashCount | Integer | Number of times to flash the Download Manager's taskbar entry when the DM is not in the foreground. Set to 0 to disable flashing. Default value is 2. |
browser. download. manager. focusWhenStarting | Boolean | True: Set the Download Manager window as active when starting a download False (default): Leave the window in the background when starting a download |
browser. download. manager. openDelay | Integer | If a download takes less than this number of milliseconds to complete, do not open the Download Manager window. Default value is 0 (always show Download Manager window). |
browser. download. manager. retention | Integer | When to remove downloaded files' entries from the Download Manager 0: Upon successful download 1: When the browser exits 2 (default): Manually Note: In Firefox, this can be changed via "Tools → Options → Privacy → Download Manager History" |
browser. download. manager. showAlertInterval | Integer | Number of milliseconds after downloads complete to show the "completed" alert. Default value is 2000. |
browser. download. manager. showAlertOnComplete | Boolean | True (default): popup window at bottom right corner of the screen will appear once all downloads are finished. False: the popup window will not appear. |
browser. download. manager. showWhenStarting | Boolean | True (default): Show Download Manager window when a download begins False: Opposite of the above Note: In Firefox, this can be changed via "Tools → Options → Downloads → Download Manager → Show Download Manager window when a download begins" |
browser. download. manager. useWindow | Boolean | True: Use the Download Manager window for downloads False: Opposite of the above Note: In Firefox, this is effectively the same as setting browser.download.manager.showWhenStarting to false; the Download Manager is used for downloads regardless of the setting |
browser. download. save_converter_index | Integer | The format to save web pages in 0: Web Page (Complete) 1: Web Page (HTML Only) 2: Text Note: In Firefox, this setting is remembered from the option you choose in the Save As dialog. |
browser. download. useDownloadDir | Boolean | True (default): Without asking a location, download files to the directory specified in browser.download.folderList False: Ask where to save every file Note: In Firefox, this can be changed via "Tools → Options → Downloads → Download Folder → Ask me where to save every file" |
browser. enable_automatic_image_resizing | Boolean | True (default): When viewing an image not in a web page, the image will be resized to fit in the browser window if it is too large for the browser window. The image can be shown in its real size by left clicking on it. False: Images are always shown in their real size. Note: In Firefox, this can be changed via "Tools → Options → Advanced → Multimedia → Resize large images to fit in the browser window" |
browser. fixup. alternate. enabled | Boolean | True (default): Try to fix up http://foo to http://(prefix)foo(suffix) False: Do not second-guess the user |
browser. fixup. alternate. prefix | String | The prefix to prepend when attempting to fix an entered URL. Default is "www." (includes full stop). Requires browser.fixup.alternate.enabled be true. |
browser. fixup. alternate. suffix | String | The suffix to append when attempting to fix an entered URL. Default is ".com". Requires browser.fixup.alternate.enabled be true. |
browser. fixup. hide_user_pass | Boolean | True (default): When attempting to fix an entered URL, do not fix an entered password along with it (i.e. do not turn http://user:password@foo into http://user:password@(prefix)foo(suffix) but instead http://user@(prefix)foo(suffix)) False: Include entered password in fixed URL |
browser. formfill. enable | Boolean | True (default): Save information entered in web page forms and the search bar False: Opposite of the above Note: In Firefox, this can be changed via "Tools → Options → Privacy → Saved Form Information → Save information I enter in web page forms and the Search Bar" |
browser. forms. submit. backwards_compatible | Boolean | True (default): Leave off mandatory Content-Transfer-Encoding header when doing form submitsFalse: Send header as the spec requires Note: Sending the header "used to cause Bad Things, including server crashes" according to comments in the Mozilla source. Eventually this pref may disappear. |
browser. frames. enabled | Boolean | True (default): Enables the display of HTML frames False: Opposite of the above; displays <noframes> content instead
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browser. goBrowsing. enabled | Boolean | True (default): If a normal DNS lookup times out, try hitting Google False: Opposite of the above Note: No longer used |
browser. helperApps. alwaysAsk. force | Boolean | True: Always ask what to do with an unknown MIME type, and disable option to remember what to open it with False (default): Opposite of above |
browser. helperApps. neverAsk. openFile | String | A comma-separated list of MIME types to open directly without asking for confirmation. Default value is an empty string. |
browser. helperApps. neverAsk. saveToDisk | String | A comma-separated list of MIME types to save to disk without asking what to use to open the file. Default value is an empty string. |
browser. hiddenWindowChromeURL | String | The chrome:// URL for the hidden window. Used in Mac OS X for when the browser is running but has no windows open. Default value is chrome://browser/content/hiddenWindow.xul |
browser. history. grouping | String | How to group entries in the history window (not applicable for Firefox's History sidebar). Default value is day. |
browser. history_expire_days | Integer | Number of days to remember visited pages in history. Default value is 9. Note: In Firefox, this can be changed via "Tools → Options → Privacy → History → Remember visited pages for the last ___ days" |
browser. link. open_external | Integer | Where to open links sent to the browser from an external application 2: Opens external links in a new window 3: Opens external links in a new tab 1 (or anything else) (default): Opens external links in current window Note: In Firefox, this can be changed via "Tools → Options → Advanced → Tabbed Browsing → Open links from other applications in:" |
browser. link. open_newwindow | Integer | Where to open links that would normally open in a new window 2 (default): In a new window 3: In a new tab 1 (or anything else): In the current window |
browser. link. open_newwindow. restriction | Integer | Firefox only. Source: The Burning Edge. 0 (default): Force all new windows opened by Javascript into tabs. 1: Let all windows opened by Javascript open in new windows. (Default behavior in IE.) 2: Catch new windows opened by Javascript that do not have specific values set (how large the window should be, whether it should have a status bar, etc.) This is useful because some popups are legitimate — it really is useful to be able to see both the popup and the original window at the same time. However, most advertising popups also open in new windows with values set, so beware. |
browser. link. open_newwindow. ui | Integer | Determine which new window open options are available from the UI. No longer used in Firefox 1.0. Default value is 3. |
browser. offline | Boolean | Status of the "Work Offline" option True: Attempt to retrieve pages from cache. Do not make external connections to retrieve resources. False (default): Assume a connection is present and retrieve resources where necessary. Note: In Firefox, this can be changed via "File → Work Offline" |
browser. popups. showPopupBlocker | Boolean | True (default): Show an icon in the status bar when a popup has been blocked. False: Do not show an icon in the status bar when a popup has been blocked. |
browser. preferences. animateFadeIn | Boolean | True (default on all platforms but Mac): When switching prefs panels, change the height of the window and fade the new panel in over about a second. False: Do not animate switching pref panels Note: This feature is only available in the Firefox trunk builds (1.1) |
browser. preferences. instantApply | Boolean | True (default on all platforms but Windows): Changes to preferences are active immediately. The preferences window is not modal. Instead of "OK" and "Cancel" buttons, there is only a "Close" button. False: Changes to preferences occur after clicking "OK" button. The preference window is modal. Note: This feature is only available in the Firefox trunk builds (1.1) |
browser. preferences. lastpanel | Integer | Which part of the preferences window was displayed the last time it was closed. In Firefox: 0: General 1: Privacy 2: Web Features 3: Downloads 4: Advanced Note: In Firefox, this is determined by the section of "Tools → Options" you are viewing when you close the dialog. |
browser. related. autoload | Integer | Automatically load "What's Related" for a given URL 0: Always 1 (default): After first use (default) 2: Never Note: This is not used in Firefox (there is no "What's Related"). |
browser. related. disabledForDomains | String | A comma-separated list of domains for which "What's Related" is disabled. Default value is an empty string. Note: This is not used in Firefox (there is no "What's Related"). |
browser. related. enabled | Boolean | Setting for "What's Related" True (default): Enable False: Disable Note: This is not used in Firefox (there is no "What's Related"). |
browser. related. provider | String | The URL to retrieve "What's Related" data from. Default value is http://www-rl.netscape.com/wtgn? Note: This is not used in Firefox (there is no "What's Related"). |
browser. search. basic. min_ver | String | Version number used to determine which search engine plugins should be installed/displayed. Default value is 0.0. |
browser. search. defaultenginename | String | Default search engine plugin to use. Default value is Google. |
browser. search. defaulturl | String | URL to prepend to search terms. Default value is http://www.google.com/search?lr=&ie=UTF-8&oe=UTF-8&q= |
browser. search. order. (number) | String | (number) is a digit used to weight the search engine specified by the value for sorting in the list of search engines. |
browser. search. order. (name) (. digit) | String | Used for weighting search engine entry sorting. Points to .properties file.
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browser. search. param. (name). (digit). ("custom" or "default") | String | Used for weighting search engine entry sorting. Points to .properties file.
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browser. search. selectedEngine | String | Name of currently selected search engine plugin |
browser. sessionhistory. max_entries | Integer | The maximum number of pages in the browser's session history, i.e. the maximum number of URLs you can traverse purely through the Back/Forward buttons. Default value is 50. |
browser. shell. checkDefaultBrowser | Boolean | Check the OS' default browser on startup. True (default): Check to see if the browser is set as default; if not, ask if the user wants it set that way False: Do not perform the check Note: In Firefox, this can be changed via "Tools → Options → General → Default Browser" |
browser. startup. homepage | String | URL of homepage, or pipe (| )-separated list of URLs to open in tabs when going to the homepageNote: In Firefox, this can be changed via "Tools → Options → General → Homepage" |
browser. startup. homepage_override. 1 | Boolean | Stub for browser.startup.homepage_override (used in Netscape 4.x). No longer used. Default value is false. |
browser. startup. homepage_override. mstone | String | The last browser version (milestone) this profile was loaded with. If it differs from the current version, pref is changed to current version. |
browser. startup. homepage_reset | String | If, during installation, the user requested that their homepage be reset, get the new homepage value from this location. Default value is resource:/browserconfig.properties |
browser. startup. page | Integer | Page to open on browser startup 0: Blank 1 (default): Home (a.k.a. browser.startup.homepage) 2: Last (probably does not work) |
browser. tabs. autoHide | Boolean | Behavior for the tab bar when only one tab exists True (default): Hide the tab bar False: Always show the tab bar Note: In Firefox, this can be changed via "Tools → Options → Advanced → Tabbed Browsing → Hide the tab bar when only one web site is open" |
browser. tabs. forceHide | Boolean | Display of the tab bar True: Hide the tab bar regardless of number of tabs False (default): Show tab bar normally |
browser. tabs. loadBookmarksInBackground | Boolean | True: When you open a bookmark in a new tab then that tab will load in the background without taking focus from the current tab. False (default): When you open a bookmark in a new tab then that tab will become the current tab. Note: In Firefox, this can be changed via "Tools → Options → Advanced → Tabbed Browsing → Select New Tabs from Bookmarks or History" |
browser. tabs. loadDivertedInBackground | Boolean | True: Any page that is supposed to open in a new window (target="_new" or from an external program) that instead gets diverted into a new tab will load in the background.False (default): Any page that is supposed to open in a new window ( target="_new" or from an external program) that instead gets diverted into a new tab will load in the foreground taking the focus from the current tab.
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browser. tabs. loadFolderAndReplace | Boolean | True (default): When opening a folder of bookmarks in tabs, the existing tabs will be replaced by the new bookmark pages. False: Existing tabs will be preserved when loading a folder of bookmarks. The bookmark pages will be loaded in tabs that are appended to the current tabs. |
browser. tabs. loadGroup | Integer | 0: Append group to current tab set 1 (default): Replace current tab set with group Note: This appears to be deprecated in favor of browser.tabs.loadFolderAndReplace |
browser. tabs. loadInBackground | Boolean | Focus behavior for new tabs True (default): Focus new tabs opened from links (bring to foreground) False: Opposite of above Note: In Firefox, this can be changed via "Tools → Options → Advanced → Tabbed Browsing → Select new tabs opened from links" |
browser. tabs. loadOnNewTab | Integer | Determines what will be displayed in a new tab -1: Browser startup page 0 (default): Blank page 1: Homepage 2: Last visited page Note: Does not work in Firefox 1.0 (See Bug 269664) |
browser. tabs. opentabfor. bookmarks | Boolean | Controls if a clicked bookmark will open in a new tab when middleclicked. Note: Pref removed (obsolete). Functionality proposed as enhancement request. |
browser. tabs. opentabfor. middleclick | Boolean | Determines the behavior of a link when middle-clicked. True (default): Opens link in new tab False: Opens link in new window |
browser. tabs. opentabfor. urlbar | Boolean | Determines the behavior of pressing Enter in the address bar or clicking the Go button. Does not currently work. True (default): Open URL in new tab False: Open URL in current tab Note: Functionality proposed as enhancement request. |
browser. tabs. opentabfor. windowopen | Boolean | Pref removed (obsolete). |
browser. tabs. showSingleWindowModePrefs | Boolean | Determines whether to display "Single Window Mode" settings in preferences. (See Bug 266759.) True: Show "Force links that open in new windows to open in..." options under "Tools → Options → Advanced → Tabbed Browsing" False (default): Opposite of above |
browser. tabs. warnOnClose | Boolean | True (default): The broswer will prompt for confirmation when closing the browser when more than one tab is open. False: No warnings will be given when closing the browser with more thanone tab. Note: In Firefox, this can be changed via "Tools → Options → Advanced → Tabbed Browsing → Warn when closing multiple tabs" |
browser. throbber. url | String | Indicates what URL to load when the throbber is clicked. Default value is http://www.mozilla.org/products/firefox/central.html |
browser. trim_user_and_password | Boolean | Seemingly nothing. (Never referenced in code.) |
browser. turbo. enabled | Boolean | Determined whether to load browser in "Turbo Mode" (aka "quick launch") (Windows/Mozilla Suite only) True: Load some Mozilla code into memory on Windows boot False (default): Load browser normally on program execution Note: Pref removed (obsolete). |
browser. underline_anchors | Boolean | Determines default text-decoration of anchor elements. True (default): Underlines links False: Opposite of above Note: In Firefox, this can be changed via "Tools → Options → General → Fonts & Colors → Underline links" |
browser. update. resetHomepage | Boolean | Determine whether to reset homepage during browser installation True: Reset homepage in browser.startup.homepage to value in browser.startup.homepage_reset False (default): Do not reset homepage |
browser. urlbar. autoFill | Boolean | True: Enables inline autocomplete. False (default): Opposite of above. |
browser. urlbar. clickSelectsAll | Boolean | True (default): Select the contents of the address bar when it is clicked False: Opposite of above |
browser. urlbar. matchOnlyTyped | Boolean | Determines behavior of autocomplete in Location bar True: Only matches typing against URLs specifically typed into Location bar |
browser. visited_color | String | The default color for visited links as a hex code. Default is #551A8B Note: In Firefox, this can be changed via "Tools → Options → General → Fonts & Colors → Visited Links" |
browser. windows. loadOnNewWindow | Integer | Set what should be displayed in a newly created window -1: Browser Startup Page 0: Blank Page 1 (default): Your Homepage 2: Last Visited |
browser. xul. error_pages. enabled | Boolean | True: The browser will use error pages. False (default): The browser will use error alert boxes. |
DOM.*
Name | Type | Meaning of Values |
---|---|---|
dom. allow_scripts_to_close_windows | Boolean | Determines which close() operations are legal.True: Any script may close any window False (default): Only windows opened via script may be closed via close() .
|
dom. disable_image_src_set | Boolean | Determines whether scripts may change the .src member of image objects (effectively, whether images can be changed via Javascript)True: Scripts may not modify .src of imagesFalse (default): Opposite fo above Note: In Firefox, this can be changed via "Tools → Options → Web Features → Enable Javascript / Advanced → Allow scripts to change images" |
dom. disable_open_click_delay | Integer | If a popup will be created as the result of a setTimeout() or setInterval() Javascript call and the delay specified is smaller than this value (in milliseconds), handle the popup according to the current popup blocker settings. Default value is 1000.
|
dom. disable_open_during_load | Boolean | Determines popup blocker behavior True (default): Block popup windows created while the page is loading False: Allow popup windows Note: In Firefox, this can be changed via "Tools → Options → Web Features → Block Popup Windows" |
dom. disable_window_flip | Boolean | Determines whether windows can be focus() ed via non-chrome Javascript.True: Windows may not be set as active via Javascript False (default): Opposite of the above Note: In Firefox, this can be changed via "Tools → Options → Web Features → Enable Javascript / Advanced → Allow scripts to raise or lower windows" |
dom. disable_window_move_resize | Boolean | Determines whether windows can be moved or resized via non-chrome Javascript. True: Windows may not be moved or resized via Javascript False (default): Opposite of the above Note: In Firefox, this can be changed via "Tools → Options → Web Features → Enable Javascript / Advanced → Allow scripts to move or resize existing windows" |
dom. disable_window_open_feature. * | Boolean | Web Page authors can disable many features of a popup window that they open. Setting these preferences to true will override the author's settings and ensure that that feature is enabled and present in any popup window. close: Prevents the close button from being disabled. directories: Prevents the bookmarks toolbar from being hidden. location: Prevents the address bar from being hidden menubar: Prevents the menubar from being hidden. minimizable: Prevents popup window minimization from being disabled. personalbar: Prevents the bookmarks toolbar from being hidden. resizable: Prevents popup window resizing from being disabled. scrollbars: Prevents the scrollbars on a popup from being disabled. status: Prevents the status bar from being hidden. titlebar: Prevents the title bar from being hidden. toolbar: Prevents the navigation toolbar from being hidden. |
dom. disable_window_status_change | Boolean | Determines whether the text in the browser status bar may be set by non-chrome Javascript. True (default): Javascript access to window.status is disabledFalse: Opposite of the above Note: In Firefox, this can be changed via "Tools → Options → Web Features → Enable Javascript / Advanced → Allow scripts to change status bar text" |
dom. event. contextmenu. enabled | Boolean | Determines whether the oncontextmenu event can be caught by non-chrome Javascript (e.g., in an anti-right-click script).True (default): the opposite of below. False: Webpages will not be able to affect the context menu event, thus allowing to access the context menu all the time. Note: in Firefox, this can be changed via "Tools → Options → Web Features → Advanced → Allow scripts to disable or replace context menus" |
dom. max_script_run_time | Integer | Determines the maximum amount of time in seconds a script can run. Default value is 5. Negative values are ignored and 5 seconds is used instead. |
dom. popup_allowed_events | String | A space-separated list of the events that are allowed to create popups. Default value is "change click dblclick mouseup reset submit ".
|
dom. popup_maximum | Integer | The maximum number of simultaneously open popup windows. Default value is 20. |
Editor.*
These settings affect libeditor (i.e. Composer and Mail). They have no(?) effect in Firefox.
Name | Type | Meaning of Values |
---|---|---|
editor. css. default_length_unit | String | Determines the default units for CSS rules. cm: centimeters em: ems (width of the capital letter "M") ex: ex (height of the lower-case "x") in: inches mm: milimeters %: percentage of parent element pc: picas (1/6th of an inch) px (default): pixels pt: points (1/72nd of an inch) |
editor. htmlWrapColumn | Integer | The column at which HTML source wraps. Default value is 72. |
editor. positioning. offset | Integer | The default offset, both X and Y, of absolutely positioned elements. Default value is 0. |
editor. quotesPreformatted | Boolean | Originally meant to be a temporary preference to control the behavior of plaintext quotations inserted into email. True: Wrap quoted email text in a pre elementFalse (default): Wrap quoted email text in a span element
|
editor. resizing. preserve_ratio | Boolean | Determines the behavior of resizing images in Composer. True (default): Preserve ratio of image while resizing False: Allow free resizing of height and width |
editor. singleLine. pasteNewlines | Integer | Determines the behavior when pasting content containing newlines into single-line text boxes. 0: Paste content intact (include newlines) 1 (default): Paste the content only up to (but not including) the first newline 2: Replace each newline with a space 3: Remove all newlines from content 4: Substitute commas for newlines in text box |
editor. use_css | Boolean | Determines the preferred method of formatting content. True (default): Use CSS styling where appropriate False: Use non-CSS methods of styling content |
editor. use_custom_colors | Boolean | Determines whether to use user-specified colors for content. True: Use colors specified in editor.* preferences for content False (default): Use the default colors |
Font.*
The majority of the font.* entries are of the form:
font.(font property).(font type).(language code)
The (font property) indicates that the value of the entry is one of the following:
- name-list
- A comma-and-space-delimited list of font names corresponding to the (font type) and (language code) (String)
- name
- A font name (String)
- size
- The font size, in pixels (Integer)
The (font type) indicates which CSS generic-family
is being referenced in the value, or simply whether the font is fixed-width or variable-width. The (font type) is one of the following:
- serif
- (e.g. Times)
- sans-serif
- (e.g. Helvetica)
- cursive
- (e.g. Zapf-Chancery)
- fantasy
- (e.g. Western)
- monospace
- (e.g. Courier)
- fixed
- Any fixed-width font
- variable
- Any variable-width font
The (language code) is an ISO 639-2 value.
Other font.* entries are listed below.
Name | Type | Meaning of Values |
---|---|---|
font. default | String | The default generic-family to use.serif (default): Serif sans-serif: Sans-serif |
font. language. group | String | The user's language group. Pulled from the localized data at chrome://global/locale/intl.properties by default on installation. |
font. size. nav4rounding | Boolean | Unused (obsolete). Previously: True: In Windows, adjust rounding of some pixel font sizes to match Netscape 4.x's (incorrect) rounding False (default): Display fonts normally |
General.*
Name | Type | Meaning of Values |
---|---|---|
general. autoScroll | Boolean | Status of the autoscroll option (middle-clicking on a web page produces a scrolling icon and will automatically scroll the page based on the pointer's relative location to the icon) True (default): Activate autoscroll False: Opposite of the above Note: In Firefox, this can be changed via "Tools → Options → Advanced → Browsing → Use autoscrolling" |
general. config. obscure_value | Integer | An integer to use when obscuring the preferences file saved to and read from disk. Default value is 13 (effectively, ROT-13 the content). |
general. skins. selectedSkin | String | The current skin used by the browser. Default value is classic/1.0. Note: In Firefox, this can be changed via "Tools → Themes" |
general. smoothScroll | Boolean | Status of ths smooth scrolling option (scrolling on a web page moves page content pixelwise rather than line-by-line) True: Activate smooth scrolling False (default): Opposite of the above Note: In Firefox, this can be changed via "Tools → Options → Advanced → Browsing → Use smooth scrolling" |
general. startup. browser | Boolean | True (default): When launching Mozilla, load the browser component False: Opposite of the above Note: This preference has little to no significance in Firefox, as it is only a browser. |
general. useragent. contentlocale | String | The content locale ISO 639-2 value specified in the User-Agent string
|
general. useragent. locale | String | ISO 639-2 value representing the user's language for the User-Agent string
|
general. useragent. override | String | A complete User-Agent string to use in place of the default.
|
general. useragent. security | String | Security level of the browser in the User-Agent stringN: No security U (default): Strong security I: Weak security |
general. useragent. vendor | String | Vendor in the User-Agent string. Default value depends on browser (Firefox in Firefox 1.0).
|
general. useragent. vendorSub | String | Vendor substring in the User-Agent string. Default value depends on browser version (1.0 in Firefox 1.0)
|
Intl.*
Name | Type | Meaning of Values |
---|---|---|
intl. charset. detector | String | Determines which locale URI sets how character set are detected in the browser |
intl. charsetmenu. browser. cache | String | A comma-and-space-delimited list of cached character sets for the browser |
intl. charsetmenu. browser. cache. size | Integer | Number of character sets to cache. Default value is 5. |
intl. charsetmenu. browser. more* | String | A comma-and-space-delimited list of character sets to display in the character encoding menu Note: In Firefox, these menus are viewable via "View → Character Encoding → More Encodings" |
intl. charsetmenu. browser. static | String | A comma-and-space-delimited list of character sets to always display in the character encoding menu. Note: In Firefox, this can be changed via "View → Character Encoding → Customize List" |
intl. charsetmenu. browser. unicode | String | A comma-and-space-delimited list of Unicode character sets to display in the character encoding menu Note: In Firefox, this menus is viewable via "View → Character Encoding → More Encodings → Unicode" |
intl. charsetmenu. composer. cache | String | A comma-and-space-delimited list of cached character sets for Composer |
intl. charsetmenu. mailedit | String | Determines the layout of the Character Coding menu in Mozilla Mail/News (message editor) |
intl. charsetmenu. mailview. cache | String | A comma-and-space-delimited list of cached character sets for Mozilla Mail/News (main view) |
intl. collationOption | String | A workaround to get correct column sorting in Mozilla Mail in Japanese builds of Linux. Default value is an empty string. Setting it to useCodePointOrder enables the workaround. (See Bug 18338) |
intl. content. langcode | String | Default content language code |
intl. fallbackCharsetList. (character set) | String | Determines the substitute character set if (character set) is unavailable. |
intl. jis0208. map | String | Determines the map to use for JIS X 0208 CP932 (default in Windows): Use a CP932-compatible map IBM943 (default in OS/2): Use an IBM943-compatible map |
intl. locale. matchOS | Boolean | Determines how to decide locale True: Use the locale the OS is using False (default): Opposite of the above |
intl. menuitems. alwaysappendaccesskeys | String | Specifies URI to determine if access keys are appended to menu items |
Javascript.*
Name | Type | Meaning of Values |
---|---|---|
javascript. allow. mailnews | Boolean | Determines whether Javascript can be executed in Mozilla Mail/News. True: Enable Javascript False (default): Disable Javascript |
javascript. enabled | Boolean | Determines whether Javascript can be executed in the browser. True (default): Enable Javascript False: Disable Javascript Note: In Firefox, this can be changed via "Tools → Options → Web Features → Enable JavaScript" |
javascript. options. showInConsole | Boolean | Determines whether chrome errors should be displayed in the JavaScript Console. True: Show chrome errors in the console False (default): hide errors |
javascript. options. strict | Boolean | Determines whether to enable strict Javascript warnings in the JavaScript Console. True: Enable strict Javascript error reporting False (default): Opposite of the above |
Layout.*
Name | Type | Meaning of Values |
---|---|---|
layout. enable_japanese_specific_transform | Boolean | Determines whether or not to replace backslashes with Yen signs in documents encoded in one of Japanese legacy encodings (EUC-JP, Shift_JIS, ISO-2022-JP) True: Replace backslashes False (default): Opposite of the above |
layout. frames. force_resizability | Boolean | Determines whether frame noresize attribute is honored.True: All frames will be resizable, resulting in a movable separator between frames. False (default): The resizability of frames is determined by the web page. |
layout. word_select. eat_space_to_next_word | Boolean | Determines whitespace selection behavior when double-clicking a word True (default): Select the space up to but not including the next word along with the word False: Just select the word with no extra whitespace |
layout. word_select. stop_at_punctuation | Booelan | Determines punctuation selection behavior when double-clicking a word True (default): Don't select punctuation automatically with the word False: Select the punctuation as well as the word |
Middlemouse.*
Name | Type | Meaning of Values |
---|---|---|
middlemouse. contentLoadURL | Boolean | Determines how to handle middle-clicks in the content area. True (default in Linux): Go to whatever address is currently in the clipboard False (default in all but Linux): Handle middle-clicks normally. Note: No effect in Firefox |
middlemouse. openNewWindow | Boolean | Determines behavior of middlemouse.contentLoadURL when that preference is true. True (default): Open links that are middle-clicked in a new window False: Opposite of the above. Note: No effect in Firefox. |
middlemouse. paste | Boolean | Determines behavior of middle-clicks when text fields or text areas have focus. True (default in Linux): Middle-clicking a text field or area will paste whatever is in your clipboard into the text field or area. False (default in all but Linux): Opposite of the above |
middlemouse. scrollbarPosition | Boolean | Determines behavior of middle-clicks in the scrollbar. True (default in Linux): Center the scroll position on the scrollbar at the coordinates of the middle-click False (default in all but Linux): Don't move the scroll position on middle-click |
Mousewheel.*
These fall into two groups, vertical and horizontal scroll. The general form is:
- mousewheel.(modifier key).(type)
- mousewheel.horizscroll.(modifier key).(type)
Type is then one of:
- action
- integer value that determines the type of action:
- 0
- Scroll document by X lines
- 1 : Scroll document by one page
- 2 : Move back/forward in history
- 3 : Make text larger/smaller
- numlines
- number of lines to scroll by (if relevant)
- sysnumlines
- use system preferences to determine how many lines to scroll by
Network.*
Name | Type | Meaning of Values |
---|---|---|
network. autodial-helper. enabled | Boolean | Help Windows NT, 2000, and XP dialup a RAS connection when a network address is unreachable. True: Launch dialer when address is unreachable False (default): Display error message |
network. automatic-ntlm-auth. allow-proxies | Boolean | Enable automatic use of the operating system's NTLM implementation to silently authenticate the user with their Windows domain logon with proxy servers. (See Integrated Authentication for more information) True (default): Automatically authenticate with proxy servers False: Prompt for authentication |
network. automatic-ntlm-auth. trusted-uris | String | A comma-and-space-delimited list of URIs with which to automatically authenticate via NTLM (Windows domain logon). Default value is an empty string. (See Integrated Authentication for more information) |
network. cookie. alwaysAcceptSessionCookies | Boolean | Determines whether to accept session cookies (kept for the duration of the browser session, then removed). True: Always accept session cookies False (default): Apply current cookie policy to session cookies |
network. cookie. cookieBehavior | Integer | Determines how the browser should handle cookies. 0 (default): Enable all cookies 1: Allow cookies from originating server only 2: Disable all cookies 3: Use P3P policy to decide Note: In Firefox, this can be changed via "Tools → Options → Privacy → Cookies → Allow sites to set cookies / for the originating web site only" |
network. cookie. disableCookieForMailNews | Boolean | Determines how Mozilla Mail/News should handle cookies. True (default): Reject all cookies in Mozilla Mail/News False: Accept cookies normally |
network. cookie. enableForCurrentSessionOnly | Boolean | True: Delete all cookies at the end of the browser session False (default): Opposite of the above Note: This setting is deprecated in favor of network.cookies.lifetimePolicy (setting that to 2 is the equivalent of this preference set to True) |
network. cookie. lifetime. days | Integer | Determines the number of days to keep cookies if network.cookie.lifetimePolicy is 3. Default value is 90. |
network. cookie. lifetimePolicy | Integer | Determines how browser sets cookie lifetimes. 0 (default): Use supplied lifetime 1: Ask before accepting 2: Accept for session only 3: Cookies last for the number of days specified in network.cookie.lifetime.days |
network. cookie. p3p | String | Determines the browser's P3P handling. An 8-character string. Default value is ffffaaaa. Each position in the string may be one of the following: f: Flag the cookie a: Accept the cookie r: Reject the cookie The character positions are as follows: 1st position: First party cookies from sites with no policy 2nd position: Third party cookies from sites with no policy 3rd position: First party cookies from sites that collect personal information without permission 4th position: Third party cookies from sites that collect personal information without permission 5th position: First party cookies from sites that collect personal information only with permission 6th position: Third party cookies from sites that collect personal information only with permission 7th position: First party cookies from sites that don't collect personal information 8th position: Third party cookies from sites that don't collect personal information |
network. cookie. p3plevel | Integer | Security level of filtering for cookies 0: Low (use afafaaaa) 1 (default): Medium (use ffffaaaa) 2: High (use frfradaa) 3: Custom (use value in network.cookies.p3p) |
network. cookie. prefsMigrated | Boolean | Indicates whether some cookie preferences — previously stored in deprecated preferences — have been migrated to current preferences. True: Consult current preferences for cookie prefs False (default): Read deprecated preferences, update current preferences, then set this preference to true |
network. dir. format | Integer | How to format directory listings (e.g., from FTP servers) 1: Raw — exactly what comes off the network 2 (default): HTML 3: application/http-index-format (requires code to parse/display that is not present by default)
|
network. dns. disableIPv6 | Boolean | Determines whether to perform IPv6 name lookups (See Bug 68796) True: Do not perform lookups False (default): Opposite of the above |
network. dns. ipv4OnlyDomains | String | A comma-separated list of domains for which DNS lookups are for IPv4 addresses only. Default value is .doubleclick.net . (See Bug 68796.)
|
network. enableIDN | Boolean | Determines whether to use IDN (International Domain Name) support in the browser True (default): Enable IDN support False: Opposite of the above Note: In Firefox 1.0, this preference did not "stick" (See Bug 261934). Fixed in 1.0.1. |
network. enablePad | Boolean | Determines whether the browser is allowed to perform proxy autodiscovery True: Autodiscovery enabled False (default): Opposite of the above |
network. ftp. anonymous_password | String | Password to use when connecting to anonymous FTP servers. Sent if advanced.mailftp is true instead of simply "mozilla@example.com". Not set by default. |
network. ftp. idleConnectionTimeout | Integer | Time in seconds until an idle FTP connection is dropped. Default value is 300. |
network. hosts. nntp_server | String | Pref to be removed (obsolete). Previously: News server for Mozilla Mail/News. Default value is news.mozilla.org. |
network. hosts. pop_server | String | POP (incoming mail) server for Mozilla Mail/News. Default value is mail. |
network. hosts. smtp_server | String | SMTP (outgoing mail) server for Mozilla Mail/News. Default value is mail. |
network. http. accept-encoding | String | Comma-separated list of encoding types to accept from server. Sent with HTTP requests in Accept-Encoding header. Default value is gzip, deflate.Note: compress is not a supported encoding (See Bug 196406) |
network. http. accept. default | String | Comma-separated list of MIME types to accept from server. Sent with HTTP requests in Accept header. Default value is text/xml,application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5.
|
network. http. connect. timeout | Integer | Pref removed (unused). Previously: determines how long to wait for a response until registering a timeout. Default value is 30. |
network. http. default-socket-type | String | Determines the socket type to be used for normal HTTP traffic. Default value is an empty string, indicating a normal TCP/IP socket type. Seems to be unused. |
network. http. keep-alive | Boolean | Determines whether to use HTTP Keep-Alive connections. If more than one request is made, the browser attempts to reuse open connections that have been kept alive. True (default): Send Connection: keep-alive header and Keep-Alive header based on contents of network.http.keep-alive.timeoutFalse: Opposite of the above (recommended in case of problems) Note: This preference is effectively obsolete, as all connections are considered keep-alive in HTTP/1.1. |
network. http. keep-alive. timeout | Integer | Requested timeout for Keep-Alive connections in seconds. Default value is 300. |
network. http. max-connections | Integer | Determines the maximum number of simultaneous HTTP connections. Default value is 24. |
network. http. max-connections-per-server | Integer | Determines the maximum number of simultaneous HTTP connections that can be established per host. If a proxy server is configured, then the server is the proxy server. Default value is 8. |
network. http. max-persistent-connections-per-proxy | Integer | If network.http.keep-alive is true, and if a proxy server is configured, then a new connection will only be attempted if the number of active persistent connections to the server is less than this preference. Default value is 4. |
network. http. max-persistent-connections-per-server | Integer | If network.http.keep-alive is true, and if a proxy server is not configured, then a new connection will only be attempted if the number of active persistent connections to the server is less than this preference. Default value is 2. |
network. http. pipelining | Boolean | Determines whether to use HTTP/1.1 pipelining. True: Enable pipelining False (default): Disable pipelining Note: Pipelining is not well-supported by some servers and proxies. Things may break — use with caution. |
network. http. pipelining. maxrequests | Integer | Determines the maximum number of HTTP requests in the pipeline (sent sequentially without waiting for a response). Default value is 4. |
network. http. proxy. keep-alive | Boolean | Determines whether to use HTTP Keep-Alive connections when a proxy server is configured. If more than one request is made, the browser attempts to reuse open connections that have been kept alive. True (default): Send Connection: keep-alive header and Keep-Alive header based on contents of network.http.keep-alive.timeoutFalse: Opposite of the above (recommended in case of problems) Note: This preference is effectively obsolete, as all connections are considered keep-alive in HTTP/1.1. |
network. http. proxy. pipelining | Boolean | Determines whether to use HTTP/1.1 pipelining when a proxy server is configured. True: Enable pipelining False (default): Disable pipelining Note: Pipelining is not well-supported by some servers and proxies. Things may break — use with caution. |
network. http. proxy. version | String | Determines which HTTP version to use when a proxy server is configured. Default value is 1.1, though 1.0 is recommended for some finnicky proxies (such as the Junkbuster proxy). |
network. http. redirection-limit | Integer | Determines how many consecutive HTTP redirects the browser will follow. Default value is 20. Setting it to 0 will stop all redirects from occuring. Note: These are header-based redirects, not (for example) <meta http-equiv="refresh"> HTML-based redirects.
|
network. http. request. max-start-delay | Integer | Determines amount of time (in seconds) to suspend pending requests, before spawning a new connection, once the limit on the number of persistent connections per host (network.http.max-persistent-connections-per-server) has been reached. However, a new connection will not be created if max-connections (network.http.max-connections) or max-connections-per-server (network.http.max-connections-per-server) has also been reached. Default value is 10. |
network. http. request. timeout | Integer | Pref removed (unused). Previously: HTTP-specific network timeout. Default value is 120. |
network. http. sendRefererHeader | Integer | Determines when to send the Referer HTTP header.0: Never send the referring URL 1: Send only on clicked links 2 (default): Send for links and images |
network. http. sendSecureXSiteReferrer | Boolean | Determines how to handle Referer HTTP header when navigating between secure (HTTPS) hosts.True (default): Send referring URL normally (default for compatibility reasons, see Bug 141641) False: Send no referring URL |
network. http. use-cache | Boolean | Determines whether to enable caching of HTTP documents. Appears to be unused. True (default): Enable caching False: Opposite of the above |
network. http. version | String | Determines which HTTP version to use. Default value is 1.1. |
network. image. imageBehavior | Integer | Determines when images should be loaded. 0 (default): Load all images 1: Load images from same (originating) server only 2: Do not load any images Note: In Firefox, this can be changed via "Tools → Options → Web Features → Load Images / for the originating web site only" |
network. image. warnAboutImages | Boolean | Determines whether to prompt the user before loading an image. True: Load no images until user confirms False (default): Load images normally Note: Pref unused (feature disabled). See Bug 146513. |
network. negotiate-auth. delegation-uris | String | A comma-and-space-delimited list of sites for which the browser may delegate user authorization to the server. (See Integrated Authentication for more information.) Default value is an empty string. |
network. negotiate-auth. trusted-uris | String | A comma-and-space-delimited list of sites that are permitted to engage in SPNEGO authentication with the browser. (See Integrated Authentication for more information.) Default value is an empty string. |
network. online | Boolean | Indicates whether the user is currently online. Used for enabling/disabling various options in the UI. True (default): User is online False: Opposite of the above |
network. prefetch-next | Boolean | Determines whether to use link prefetching. True (default): Silently prefetch hinted documents and store in the cache False: Disable all link prefetching |
network. protocol-handler. expose-all | Boolean | Determines whether to expose (enable) all protocol handlers. This preference overrides more specific preferences, e.g. network.protocol-handler.expose.mailto. True: Try to open link clicks in browser first, then fail over to system handlers False: Do not expose all protocol handlers |
network. protocol-handler. expose. (protocol) | Boolean | Determines whether to expose (enable) the specified protocol handler. These preferences are overridden by network.protocol-handler.expose-all. True: Try to open link clicks in browser firsst, then fail over to system handlers False: Do not expose this protocol handler |
network. protocol-handler. external-default | Boolean | Determines the default action for unlisted external protocol handlers True (default): Try to load False: Opposite of the above |
network. protocol-handler. external. (protocol) | Boolean | Determines whether to allow external protocol handlers to catch links with these protocols True: Allow external handler to handle link False (default): Prevent external handler from handling this link |
network. protocol-handler. warn-external-default | Boolean | Determines whether to warn the user before loading an unlisted external handler True (default): Warn the user False: Opposite of the above |
network. protocol-handler. warn-external. (protocol) | Boolean | Determines whether to warn the user before loading this protocol's external handler True: Warn the user False (default): Opposite of the above |
Miscellaneous
Name | Type | Meaning of Values |
---|---|---|
allinonegest. * | Varied | These preferences are set via the All in One Mouse Gestures extension. |
application. use_ns_plugin_finder | Boolean | True: When a plugin is not found, clicking on the puzzle piece will open a dialog telling the user what plugin is needed. Clicking on the "Get the Plugin" button brings the user to the plugins installation page. False (default): Clicking on the puzzle piece will send the user to that plugin's page on plugins.netscape.com which will have a link to that plugin's installation page. |
backups. number_of_prefs_copies | Integer | Unused (obsolete). Previously: number of backup copies of prefs.js to keep. |
clipboard. autocopy | Boolean | True: Selecting text automatically copies it to the clipboard False (default): Opposite of the above Note: *nix only. |
config. use_system_prefs | Boolean | True: Use preferences set by operating system (e.g. proxies, accessibility) False (default): Opposite of the above Note: Seems to be unused in Firefox 1.0 |
config. use_system_prefs. accessibility | Boolean | True: The system is configured with accessibility features; use them False (default): Opposite of the above Note: Seems to be unused in Firefox 1.0 |
converter. html2txt. header_strategy | Integer | How to format HTML headers (H1-H6) when saving a web page as text-only 0: No indentation 1 (default): Indent headers based on header level (i.e. H(n+1) is indented more than H(n)) 2: Number headings and indent slightly |
converter. html2txt. structs | Boolean | Determines whether to format "structured" elements (<strong> , <em> , <code> , <sub> , <sup> , <b> , <i> , <u> ) with other characters when saving a web page as text-onlyTrue (default): *Strong* , /em/ , |code| , _sub , ^sup , *b* , /i/ , _u_ False: Strong , em , code , sub , sup , b , i , u
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custtoolbar. personal_toolbar_folder | String | Custom name for the Personal Toolbar Folder. If empty (default), name is determined by string bundle or the hard-coded value "Personal Toolbar Folder". |
extension. * | Varied | These entries are added by extensions. Most extension preferences can be edited using that extension's options dialog. Extension option dialogs are accessed using the extension manger. Not all extension options start with the extension keyword. |
image. animation_mode | String | Determines how to animate multi-frame GIF images none: animated images will never play. once: animated images will play once. normal (default): animated images will play as normal. |
images. dither | String | Whether to dither images auto (default): Automatically decide true: Dither images false: Disable image dithering |
inspector. * | Varied | These entries apply to the DOM Inspector and are only relevant if you have it installed. |
keyword. URL | String | URL to use for keyword lookups. Default value is http://www.google.com/search?btnI=I%27m+Feeling+Lucky&ie=UTF-8&oe=UTF-8&q= in Firefox 1.0. |
keyword. enabled | Boolean | Determines whether to use keywords True (default): Send non-URLs entered in the Location Bar to the URL specified in keyword.URL False: Disable keywords |
mail. ui. display. dateformat. today | Integer | See Change the Date Format. |
privacy. popups. disable_from_plugins | Integer | Sets limits on popups generated from plugins (e.g. Flash) 0: lets all popups through 1: limits their number to dom.popup_maximum (even with popup blocker disabled) 2: blocks popups from plugins 3: blocks them even on whitelisted sites. |
view_source. wrap_long_lines | Boolean | True: HTML code will wrap in the view source window. False (default): HTML code will not wrap in the view source window. Note: This can be changed using "View → Wrap Long Lines" in the view source window. |