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
- Choose Start → Run
- Type in %APPDATA%
- Press OK. A Windows Explorer window will appear.
- 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
- Choose Start → Start Search
- Type in %APPDATA%
- Press OK. A Windows Explorer window will appear.
- 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 | Application | Description |
|---|---|---|
| backupData | Sunbird (starting in 0.3) | Backups of your calendars. |
| bookmarkbackups | Firefox (starting in 1.5) | Daily rotating backups of your bookmarks. |
| Cache | Firefox, SeaMonkey | Cached Internet files. Folder location changed in Firefox 1.5 [1]. Use about:cache for information about the cached files and to find the Cache folder location. |
| chrome | Firefox, Thunderbird, SeaMonkey, Sunbird | (In Firefox 1.5, Thunderbird 1.5 and Sunbird 0.3, the chrome folder is only used for userChrome.css and userContent.css) |
| extensions | Firefox, Thunderbird, SeaMonkey, Sunbird | Installed extensions |
| ImapMail | Thunderbird, SeaMonkey | Mail from IMAP sources |
| Thunderbird, SeaMonkey | Mail from POP sources and Local Folders | |
| microsummary-generators | Firefox (starting in 2.0) | Regularly-updated succinct compilations of the most important information on web pages. |
| News | Thunderbird, SeaMonkey | News from newsgroups |
| searchplugins | Firefox (starting in 1.5) | Contains search engine plugins and their icons for the Search Bar |
Files
| Name | Application | Description |
|---|---|---|
| .autoreg | Firefox, SeaMonkey, Thunderbird, Sunbird | Temporary empty file that signals a change in the installed extensions. |
| .parentlock | Firefox, SeaMonkey, Thunderbird (MacOS X) | See parent.lock |
| abook.mab | Thunderbird, SeaMonkey | Personal Address Book |
| blocklist.xml | Firefox, Thunderbird (starting in 2.0) | Automatically downloaded list of dangerous extensions. |
| bookmarks.bak | Firefox | Backup of bookmarks.html (Bug 218636) |
| bookmarks.html | Firefox, SeaMonkey | Bookmarks |
| bookmarks.html.moztmp | Firefox, SeaMonkey | 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 | Firefox (starting in 1.5) | Daily rotating backups of your bookmarks. |
| cert8.db | Firefox, SeaMonkey, Thunderbird, Sunbird | Security certificates |
| compatibility.ini | Firefox, Thunderbird, Sunbird | 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 | Firefox, Thunderbird | Lists extension folders with XPCOM components. Replaced with extensions.ini in 1.5. |
| compreg.dat | Firefox, Thunderbird, Sunbird | Lists registered XPCOM components. Automatically regenerated whenever XPCOM registration process is triggered. |
| cookies.txt | Firefox, Thunderbird, SeaMonkey | Cookies RSS_cookies_(Thunderbird) |
| cookies.txt.moztmp | Firefox, SeaMonkey | 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 | Firefox, Thunderbird (before 1.5) | Lists extension folders with default pref files. Replaced with extensions.ini in 1.5. |
| downloads.rdf | Firefox, Thunderbird, SeaMonkey | Download history. Can be deleted to resolve slow downloads or program hangs (Bug 159107) |
| extensions.cache | Firefox, Thunderbird (starting in 1.5), Sunbird | 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 | Firefox, Thunderbird (starting in 1.5), Sunbird | 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 | Firefox, Thunderbird | Installed extension information. Can be deleted in Firefox 1.5 or Thunderbird 1.5 to remove "ghost" entries from the extension list [2] and to resolve various other issues. |
| extensions-startup.manifest | Firefox and Thunderbird 1.5 alphas | This file was used in Deer Park alphas and was later renamed to extensions.cache |
| formhistory.dat | Firefox | Saved form data |
| history.dat | Firefox, Mozilla Suite | Browsing history. Can be deleted to resolve various issues. |
| history.mab | Thunderbird, SeaMonkey | Collected Addresses |
| hostperm.1 | Firefox, SeaMonkey | Per-site preferences for allowing cookies and popups. |
| key3.db | Firefox, SeaMonkey, Thunderbird, Sunbird | Key database |
| kf.txt | Firefox (starting in 2.0) | Key database for phishing protection. |
| localstore.rdf | Firefox, Thunderbird, SeaMonkey, Sunbird | Toolbar and window size/position settings. Can be deleted to resolve various issues. |
| localstore-safe.rdf | Firefox (starting in 1.5) | Special version of localstore.rdf used in Safe Mode to set toolbars and window customizations to defaults. [3] |
| lock (Linux) | Firefox, Thunderbird, SeaMonkey | See parent.lock |
| mailviews.dat | Thunderbird, SeaMonkey | Defines your current message view (you can customize it) |
| mimeTypes.rdf | Firefox, Thunderbird, Sunbird, SeaMonkey | Action to perform when downloading certain types of files. Can be deleted to reset download actions. |
| msgFilterRules.dat in ImapMail, Mail, News | Thunderbird, SeaMonkey | Message filters |
| nsmail.eml, nsmail.tmp, nsmail.html | Thunderbird, SeaMonkey | Temporary files created when sending a message. |
| panacea.dat | Thunderbird, SeaMonkey | Mail folder cache |
| parent.lock | Firefox, SeaMonkey, Thunderbird (Windows) | Marker showing that the current profile is in use. Can be deleted to unlock the profile. |
| persdict.dat | Thunderbird, SeaMonkey | Personal spelling dictionary |
| popstate.dat in Mail | Thunderbird | Keeps track of which messages have been left on the POP3 server |
| prefs.js | Firefox, Thunderbird, Sunbird, SeaMonkey | All preferences. See: about:config |
| search.rdf | Firefox | Information about your search plug-ins |
| search.sqlite | Firefox (starting in 2.0) | Information about your search plug-ins |
| secmod.db | Firefox, Thunderbird, Sunbird, SeaMonkey | Security module database |
| sessionstore.js | Firefox (starting in 2.0) | Stored session. |
| signons.txt | Firefox, Sunbird | Encrypted saved passwords, requires key3.db to work |
| signons2.txt | Firefox (starting in 1.5.0.10 & 2.0.0.2) | Encrypted saved passwords, requires key3.db to work [4] |
| storage.sdb | Sunbird (from 0.3) | Internal calendar data (in SQLite format) |
| training.dat | Thunderbird | Custom training for Junk Mail Controls |
| tmprules.dat | Thunderbird | Temporary file used when modifying message filters. |
| urlclassifier.sqlite | Firefox (starting in 2.0) | Phishing protection data. |
| user.js (does not exist by default) |
Firefox, Thunderbird, Sunbird, SeaMonkey | User-set overriding preferences |
| userChrome.css in chrome (does not exist by default) |
Firefox, Thunderbird, Sunbird, SeaMonkey | User-set CSS to change the way the application looks |
| userContent.css in chrome (does not exist by default) |
Firefox, Thunderbird, Sunbird, SeaMonkey | User-set CSS to change the way webpages look |
| userChrome.js in chrome (does not exist by default) |
Firefox, Thunderbird, Sunbird, SeaMonkey | User-set JavaScript to change the way the application works |
| virtualfolders.dat | Thunderbird | Saved Search folder settings |
| webappsstore.sqlite | Firefox (starting in 2.0) | Session storage. |
| xpti.dat | Firefox, Thunderbird, Sunbird | Lists registered XPCOM interfaces. Automatically regenerated whenever XPCOM registration process is triggered. |
| xul.mfasl | Firefox, Thunderbird (Linux) | See XUL.mfl |
| XUL.mfl | Firefox, Thunderbird (Windows), Sunbird, SeaMonkey | Cached user interface data. Can be deleted to resolve various issues (file location changed in Firefox 1.5, Thunderbird 1.5 [5]) |
| XUL FastLoad File | Firefox, Thunderbird (MacOS X) | See XUL.mfl |
Files without specific names
| Name | Application | Description |
|---|---|---|
| (number).s | Thunderbird, SeaMonkey | Password data. The "(number).s" value is referenced in the about:config preference "signon.SignonFileName" preference |
| (number).w | SeaMonkey | Saved form data |
| *. in ImapMail, Mail, and News | Thunderbird | Mail messages |
| *.mab other than abook.mab and history.mab | Thunderbird, SeaMonkey | User-created address books |
| *.msf in ImapMail, Mail, and News | Thunderbird | Index files for mail messages |
| *.src in searchplugins | Firefox | Search engine plugins for the Search Bar |
Files outside the "Profiles" folder
| Name | Application | Description |
|---|---|---|
| pluginreg.dat | Firefox, Thunderbird | Registration of plugin mimetypes. Located in the <parent> folder containing the "Profiles" folder. |
| profiles.ini | Firefox, Thunderbird | 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 | Firefox, Thunderbird, SeaMonkey | Keeps track of where your profiles are located in SeaMonkey and in older Firefox and Thunderbird versions. Located in the <parent> folder containing the "Profiles" folder. |
