Profile folder - Firefox

This article is about Firefox's profile folder. See also Profile folder - Thunderbird and Profile folder - SeaMonkey.

Firefox stores a user's personal information such as bookmarks, extensions, and user preferences in a unique profile. The first time you start Firefox, it will automatically create a default profile; additional profiles can be created using the Profile Manager. The settings which form a profile are stored in files within a special folder on your computer — this is the profile folder.

Finding the profile folder

Profile folders are placed in the same area by default but are named randomly for additional security. If you chose a custom location, see Other methods of finding a profile below.

The installation directory includes a folder named "profile" (for example, C:\Program Files\Mozilla Firefox\defaults\profile on Windows), but this folder contains program defaults, not your user profile data.

Windows 95, 98, and ME

Profile folders are contained in C:\Windows\Application Data\Mozilla\Firefox\Profiles\ or C:\Windows\Profiles\<Windows login/user name>\Application Data\Mozilla\Firefox\Profiles\ .

Windows 2000 and XP

1. Choose Start → Run
2. Type in %APPDATA%
   
3. Press OK. A Windows Explorer window will appear.
4. In the Windows Explorer window, choose Mozilla → Firefox → Profiles. Each folder in this folder is a profile on your computer.

You can also navigate directly to your folder at the path C:\Documents and Settings\<Windows login/user name>\Application Data\Mozilla\Firefox\Profiles\ . The Application Data folder is a hidden folder; to show hidden folders, open Windows Explorer and choose "Tools → Folder Options → View (tab) → Show hidden files and folders".

Windows Vista

1. Choose Start → Start Search
2. Type in %APPDATA%
3. Press OK. A Windows Explorer window will appear.
4. In the Windows Explorer window, choose Mozilla → Firefox → Profiles. Each folder in this folder is a profile on your computer.

You can also navigate directly to your folder at the path C:\Users\<Windows login/user name>\AppData\Roaming\Mozilla\Firefox\Profiles\ . The AppData folder is folder is a hidden folder; to show hidden folders, open Windows Explorer and choose "Organize → Folder and Search Options → Folder Options → View (tab) → Show hidden files and folders".

Linux and Unix

Profile folders are contained in ~/.mozilla/firefox/ . The .mozilla folder is a hidden folder.

Mac

Profile folders are contained in ~/Library/Mozilla/Firefox/Profiles/ or ~/Library/Application Support/Firefox/Profiles/ .

Other methods of finding a profile

Specific files in profiles can be found by doing a file search. This is useful to find folders not in the default location. When searching, you must ensure that you're including hidden files and folders in the search.

• Windows 2000: In Windows Explorer, choose Tools → Folder Options → View (tab) → Show hidden files and folders
• Windows XP: Within the search tool, More Advanced Options → Search hidden files and folders
• Windows Vista: Within the search tool, More Advanced Options → Include non-indexed, hidden or system files

Managing profiles

You can select a profile to use, create a new profile, and delete or rename an existing profile using the Profile Manager. You can migrate your settings to a new profile, back up your profile, and set up a roaming profile.

Profiles can also be the cause of problems, for example "Profile is already in use" errors. Profiles can become corrupted, in which case you need to create a new profile then migrate your settings to the new profile.

If you delete, rename or move the profile folder, Firefox may report that it is "already running, but is not responding" when you next start the application (bug 278860). See this article for more information.

Files and folders in the profile

Note: It's not recommended to edit these files directly. Instead, use their respective interfaces. The three files whose names begin with "user" are exceptions to this—they are designed to be edited directly. For more information on these three files, follow their links in the tables below.

Folders

Name	Versions	Description
bookmarkbackups	1.5 and above	Daily rotating backups of your bookmarks.
Cache	Previous to 1.5.	Use about:cache for information about the cached files and to find the Cache folder location.
chrome		Contains userChrome.css and userContent.css.
extensions		Installed extensions
microsummary-generators	2.0 and above	Regularly-updated succinct compilations of the most important information on web pages.
searchplugins	1.5 and above	Contains search engine plugins and their icons for the Search Bar

Files

Name	Versions	Description
.autoreg		Temporary empty file that signals a change in the installed extensions.
.parentlock	Mac OS X	See parent.lock
blocklist.xml	2.0 and above	Automatically downloaded list of dangerous extensions.
bookmarks.bak		Backup of bookmarks.html (Bug 218636)
bookmarks.html		Bookmarks
bookmarks.html.moztmp		Temporary bookmarks file. If found, remove the 'read-only' attribute, as it results in creation of multiple numbered bookmarks-n.html files (Bug 157152).
bookmarks-(date).html in bookmarkbackups	1.5 and above.	Daily rotating backups of your bookmarks.
cert8.db		Security certificates
compatibility.ini		Stores version and path of the application this profile was last used with. When the profile is loaded with an application of a different version/path, the XPCOM components registration process is triggered. This file is automatically generated and can safely be deleted.
components.ini	Previous to 1.5.	Lists extension folders with XPCOM components. Replaced with extensions.ini in 1.5.
compreg.dat		Lists registered XPCOM components. Automatically regenerated whenever XPCOM registration process is triggered.
cookies.txt		Cookies
cookies.txt.moztmp		Temporary cookies file. If found, either delete or remove the 'read-only' attribute, as it results in creation of multiple numbered cookies-n.txt files (Bug 257288).
defaults.ini	Previous to 1.5.	Lists extension folders with default pref files. Replaced with extensions.ini in 1.5.
downloads.rdf		Download history. Can be deleted to resolve slow downloads or program hangs (Bug 159107)
extensions.cache	1.5 and above.	Lists installed extensions, their IDs, and the folders they are installed to, along with their last-modify time. It is used, for example, to register extensions installed by dropping a folder into one of known install locations. This file is automatically regenerated and can be deleted to resolve various issues.
extensions.ini	1.5 and above.	Lists folders of installed extensions and themes. The file is automatically generated by nsExtensionManager and is used by low-level code to detect chrome packages and XPCOM components provided by installed addons. Can be deleted to resolve various issues.
extensions.rdf		Installed extension information. Can be deleted to remove "ghost" entries from the extension list [1] and to resolve various other issues.
extensions-startup.manifest	1.5 alphas	This file was used in Deer Park alphas and was later renamed to extensions.cache
formhistory.dat		Saved form data
history.dat		Browsing history. Can be deleted to resolve various issues.
hostperm.1	Firefox	Per-site preferences for allowing cookies and popups.
key3.db		Key database
kf.txt	2.0 and above	Key database for phishing protection.
localstore.rdf		Toolbar and window size/position settings. Can be deleted to resolve various issues. See Corrupt localstore.rdf.
localstore-safe.rdf	1.5 and above.	Special version of localstore.rdf used in Safe Mode to set toolbars and window customizations to defaults. [2]
lock	Linux	See parent.lock
mimeTypes.rdf		Action to perform when downloading certain types of files. Can be deleted to reset download actions.
parent.lock	Windows	Marker showing that the current profile is in use. Can be deleted to unlock the profile.
prefs.js		All preferences. See: about:config
search.rdf		Information about your search plug-ins
search.sqlite	2.0 and above.	Information about your search plug-ins
secmod.db		Security module database
sessionstore.js	2.0 and above	Stored session.
signons.txt	Previous to 1.5.0.10, 2.x versions previous to 2.0.0.2.	Encrypted saved passwords, requires key3.db to work
signons2.txt	1.5.x versions after 1.5.0.10, 2.0.0.2 and later	Encrypted saved passwords, requires key3.db to work [3]
urlclassifier.sqlite	2.0 and later	Phishing protection data.
user.js (does not exist by default)		User-set overriding preferences
userChrome.css in chrome (does not exist by default)		User-set CSS to change the way the application looks
userContent.css in chrome (does not exist by default)		User-set CSS to change the way webpages look
userChrome.js in chrome (does not exist by default)		User-set JavaScript to change the way the application works
webappsstore.sqlite	2.0 and later.	Session storage.
xpti.dat		Lists registered XPCOM interfaces. Automatically regenerated whenever XPCOM registration process is triggered.
xul.mfasl	Linux	See XUL.mfl
XUL.mfl	Previous to 1.5.	Cached user interface data. Can be deleted to resolve various issues. [4])
XUL FastLoad File	MacOS X	See XUL.mfl

Files without specific names

Name	Version	Description
*.src in searchplugins		Search engine plugins for the Search Bar

Files outside the "Profiles" folder

Name	Version	Description
pluginreg.dat		Registration of plugin mimetypes. Located in the <parent> folder containing the "Profiles" folder.
profiles.ini		Keeps track of profile location. Located in the <parent> folder containing the "Profiles" folder. Can be edited to point to a moved profile folder. If deleted, profiles.ini will be regenerated along with a new default profile folder upon program restart.
registry.dat	?	Keeps track of where your profiles are located. Located in the <parent> folder containing the "Profiles" folder.

External links

• Firefox Help: How To Manage Profiles