Firefox stores your personal data and settings in a profile folder. Learn what information it contains and how to find your profile.
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What information is stored in my profile?
Note: This is not a complete list. Only important information is described.
Bookmarks, Downloads and Browsing History:
places.sqlite
This file contains all your Firefox bookmarks and lists of all the files you've downloaded and websites you’ve visited.
bookmarkbackups
This folder stores bookmark backup files, which can be used to restore your bookmarks.
favicons.sqlite
This file contains all of the favicons for your Firefox bookmarks.
For more information, see Bookmarks in Firefox and Restore bookmarks from backup or move them to another computer.
Passwords:
key4.db
logins.json
Your passwords are stored in these two files. For more information, see Password Manager - Remember, delete and edit logins and passwords in Firefox.
Site-specific preferences:
permissions.sqlite
content-prefs.sqlite
These two files store many of your Firefox permissions (for instance, which sites are allowed to display popups) or zoom levels that are set on a site-by-site basis (see Font size and zoom - increase the size of web pages).
Search engines:
search.json.mozlz4
This file stores user-installed search engines. For more information, see Add or remove a search engine in Firefox.
Personal dictionary:
persdict.dat
This file stores any custom words you have added to Firefox's dictionary. For more information, see How do I use the Firefox spell checker?.
Autocomplete history:
formhistory.sqlite
This file remembers what you have searched for in the Firefox search bar and what information you’ve entered into forms on websites. For more information, see Control whether Firefox automatically fills in forms.
Cookies:
cookies.sqlite
A cookie is a bit of information stored on your computer by a website you’ve visited. Usually, this is something like your site preferences or login status. Cookies are all stored in this file.
DOM storage:
DOM Storage is designed to provide a larger, more secure, and easier-to-use alternative to storing information in cookies.
webappsstore.sqlite
Information is stored in this file for websites
chromeappsstore.sqlite
This file stores information for about:* pages.
Extensions:
extensions
This folder, if it exists, stores files for any extensions you have installed. To learn more about Firefox extensions and other add-ons, see Find and install add-ons to add features to Firefox.
Security certificate settings:
cert9.db
This file stores all your security certificate settings and any SSL certificates you have imported into Firefox.
Security device settings:
pkcs11.txt
This file stores security module configuration.
Download actions:
handlers.json
This file stores your preferences that tell Firefox what to do when it comes across a particular type of file. For example, these are the settings that tell Firefox to open a PDF file with Acrobat Reader when you click on it. For more information, see Manage file types and download actions in Firefox.
Stored session:
sessionstore.jsonlz4
This file stores the currently open tabs and windows. For more information, see Restore previous session - Configure when Firefox shows your most recent tabs and windows.
Window positions and dialog settings:
xulstore.json
This file stores the size and position of the main Firefox window and Library window, selected columns in the Library window, and expanded folders in the Bookmarks Sidebar and History Sidebar.
User preferences:
prefs.js
This file stores customized user preference settings, such as changes you make in Firefox Settings dialogs and in customizing toolbars (Customize Firefox controls, buttons and toolbars). The optional user.js file, if one exists, will override any modified preferences.
Containers:
containers.json
This file stores the details of containers used by the Container Tabs feature, including those created by extensions such as Facebook Container.
