Files Used by Opera for Windows

This document explains the purpose of the files used by Opera for Windows. This can be useful for everyone who likes to tinker with their copy of Opera, for those who manually make separate profiles for different uses or users, or for those who have tinkered and would like to know how to survive a new installation process.

Warning: Tinkering can make your copy of Opera unusable, or cause data loss. Do not tweak while Opera is running, except when told otherwise. Deleting files will cause data loss! Always make backups before making any changes.

This document was last updated for Opera 9.10.

Note: The number in some file names does not correspond to the current Opera version but to the version in which the file format was last changed.

Profiles

There are three categories of Opera files: installation files, profile files, and mail files.

Installation files
are placed on your hard disk by the installer, in or directly under your chosen installation directory. They will generally be overwritten when you upgrade or reinstall Opera in the same directory.
Profile files
contain all data related to your preferences and browsing history and are generally not overwritten on upgrade or reinstall.
Mail files
contain all data related to your mail, newsgroups, newsfeeds, and chat accounts. They are generally not overwritten when you upgrade or reinstall Opera.

When you install Opera for the first time, you will get a choice between:

  • Using a single profile for a single-user installation. The Profile and Mail directories will then be created directly under the main installation directory, on the first run of Opera.
  • Using the Windows user system (available since Windows 98SE, used by default on Windows 2000 and Windows XP). The Profile and Mail directories will be created under <system application data folder>\Opera\<Opera installation folder name>\, the first time a user runs Opera.

Your choice between single-user and multi-user is stored in the parameter Multi User in OperaDef6.ini. This determines the location where Opera will look for the profile data when it is started. If you upgrade an existing installation, the choice will not be offered. In that case the existing settings will always be preserved, and the existing profile or profiles will automatically be reused. The active paths for the Profile and Mail directory can be found under Help > About Opera.

Directories

Installation files

main installation directory | classes | defaults | locale | program | skin | styles | uninst

Profile files

main profile directory | bt_metadata | cache4 | images | keyboard | menu | mouse | opcache | sessions | skin | styles | toolbar | UnInst | voice widgets

Mail files

main mail directory | autofilter | indexer | lexicon | store

Installation files

Main installation directory
FilenameFormatOverwrittenDescription
c3nform.vxmltext/xmlYesVxml form for c3n (Command, control, content navigation); installed automatically when enabling "Voice" in Opera
chartables.binbinaryYesTables for Unicode support
dialog.initext/plainYesDefinition of all dialogs
E1FKAL00.LEbinaryYesVoice related, for the high quality text-to-speech; installed automatically when enabling "Voice" in Opera
E1MKAN00.LEbinaryYes
ecictts.dllbinaryYesVoice related; installed automatically when enabling "Voice" in Opera
ecienus.synbinaryYes
ecissml.dllbinaryYes
english.lngtext/plainYesLanguage file, contains all text strings in Opera's user interface; when using the International installer more than 30 files for other languages are included in the locale subdirectory [1]
en-us.binbinaryYesVoice related; installed automatically when enabling "Voice" in Opera
fastforward.initext/plainYesDefines what activates the Fast Forward button; instructions for customization are included in the file
html40_entities.dtdtext/dtdYesCharacter entity set
License.txttext/plainYesLicense governing the use of the software
lngcode.txttext/plainYesList of languages and their two letter code, used in Opera when choosing preferred language (Tools > Preferences > General)
Opera.dllbinaryYesOpera program library, the main part of Opera
Opera.exebinaryYesOpera executable; wrapper for opera.dll
OperaDef6.initext/plainYesStored default program settings; see also Opera6.ini explained
ouniansi.dllbinaryYesUnicode to ANSI conversion for Windows 95/98/ME
plugin-ignore.initext/plainYesList of plug-ins that Opera will ignore because they cause serious problems for the browser
prondict.initext/plainYesEditable pronunciation dictionary for Voice. Installed automatically when enabling "Voice" in Opera
ready.pcmbinaryYesVoice related; installed automatically when enabling "Voice" in Opera
search.initext/plainYesDefault settings for the search engines available in Opera
spellcheck.dllbinaryYesSpelling check plug-in that connects Opera to Aspell
spellcheck.initext/plainYesSpecifies which plug-in is used to check spelling
vxm.dllbinaryYesVoice related; installed automatically when enabling "Voice" in Opera
vxmconfig.initext/plainYes
vxmdict_en-us.initext/plainYes
vxmplugin.dllbinaryYes
vxmservices.dllbinaryYes
xmlparse.dllbinaryYesXML parser module, only used by Voice in Opera 9
classes
FilenameFormatOverwrittenDescription
opera.jarbinaryYesConnection to the Java Runtime Engine
opera.policytext/plainYesSets permissions for Java applets running inside Opera [2]
defaults
FilenameFormatOverwrittenDescription
embedded_keyboard.initext/plainYesKeyboard shortcuts configuration used when the opera.dll is embedded in another application
embedded_menu.initext/plainYesMenu configuration used when the opera.dll is embedded in another application
embedded_mouse.initext/plainYesMouse gestures configuration used when the opera.dll is embedded in another application
operadef6.adrtext/plainYesDefault bookmarks file, will be copied to opera6.adr in new profiles
standard_keyboard.initext/plainYesOpera standard keyboard shortcuts configuration [3]
standard_menu.initext/plainYesOpera standard menu configuration [3]
standard_mouse.initext/plainYesOpera standard mouse gestures configuration [3]
standard_toolbar.initext/plainYesOpera standard toolbar configuration [3]
standard_voice.initext/plainYesOpera standard voice commands configuration [3]
locale
FilenameFormatOverwrittenDescription
*.lngtext/plainYesCollection of language files for the user interface, in a subdirectory for each language. Only installed when using the International installer. When switching preferred language in the Preferences (General tab), the matching user interface language file will be selected automatically when available. [1]
program
FilenameFormatOverwrittenDescription
netscape.exebinaryYesA very simple program that starts Opera. Some plug-ins will only install in the plug-ins folder when there is a file called 'netscape.exe' in a directory called 'programs' one level up. 'Netscape' is started after installing those plug-ins.
plugins\npds.zipbinaryYesWindows Media Player related
plugins\npdsplay.dllbinaryYesWindows Media Player related
plugins\npwmsdrm.dllbinaryYesWindows Media Player related
plugins\np*.dllbinaryNoOther installed plugins. More info on plugins for Opera.
skin
FilenameFormatOverwrittenDescription
standard_skinzipYesOpera Standard skin
windows_skinzipYesWindows Native skin
styles
FilenameFormatOverwrittenDescription
images\*.pngimage/pngYesCollection of images used by the style sheets
user\*.csstext/cssYesA collection of user style sheets. These will seed the profile\styles directory.
about.csstext/cssYesStyle sheet for the layout of the About Opera page
cache.csstext/cssYesStyle sheet for the layout of the Cache page
certinfo.csstext/cssYesStyle sheet for the layout of the certificate information dialog
config.csstext/cssYesStyle sheet for the layout of the Preferences editor
contentblock.csstext/cssYesStyle sheet for the display of pages in content blocking mode
dir.csstext/cssYesStyle sheet for the layout of directory listings
drives.csstext/cssYesStyle sheet for the layout of the local drives page
error.csstext/cssYesStyle sheet for the layout of error pages
history.csstext/cssYesStyle sheet for the layout of the History page
im.csstext/cssYesStyle sheet for the layout of chat pages
image.csstext/cssYesStyle sheet for the layout of separately displayed images
info.csstext/cssYesStyle sheet for the layout of the Info panel
mime.csstext/cssYesStyle sheet for the layout of e-mail messages and newsgroup articles
plugins.csstext/cssYesStyle sheet for the layout of the Plugins page
warning.csstext/cssYesStyle sheet for the layout of Fraud Protection warning pages
wml.csstext/cssYesStyle sheet for the layout of WML pages
uninst (only with Classic installer)
FilenameFormatOverwrittenDescription
backup\*.*variousNoFiles that are replaced during the installation with the Classic installer are backed up in this folder, to be restored if you opt for a 'rollback' uninstallation. If you perform multiple installations in the same directory, duplicate backup files will be saved with numbered file extensions.
install.logtext/plainno (logs for subsequent installations are appended to this file)Logs all actions (file copied, directories made, registry entries made etc) performed during installation; needed for properly uninstalling Opera
OpUninst.exebinaryYesProvides specific helper functions during uninstalling
OpUninst.initext/plainYesData for the Uninstall program
unwise.exebinaryYesGeneric WISE uninstall program
UnWise.initext/plainYesText strings for the Uninstall program

Profile files

Main profile directory
FilenameFormatOverwrittenDescription
browser.jstext/plainYes, after performing a manual version check and once a week automaticallyBrowser JavaScript file, automatically downloaded and updated if Browser JavaScript is enabled. The file will be ignored if edited locally. Use User JavaScript for your own scripts.
contacts.adrtext/plainNoStored contacts used for e-mail and chat. The file can be saved and renamed, and another file can be selected from the context menu on the Contacts panel
cookies4.datbinary (see description)NoStored cookies. The file is removable, but cookies can also be erased using Tools > Delete private data in Opera [5]
download.datbinaryNoStored information about recent downloads to allow resuming of downloads that were interrupted. To adjust the number of days to keep download data available, change KeepEntriesDays in opera:config
global.dattext/plainNoStored global history. Properties are set in Tools > Preferences > Advanced > History. URLs stored here are used for the auto-complete function, and can be checked from Tools > History. The file is removable, but you can also use 'Delete private data' to delete your browsing history.
notes.adrtext/plainNoStored notes from the Notes panel
opcacrt6.datbinaryNoStored CA certificates. Read more about certificates
opcert6.datbinaryNoStored personal certificates and private keys. Read more about certificates
opera.dirtext/plainNoStored 'Go to page' dialog history; can be accessed from the "Go to" dialog, or by clicking on the arrow to the right of the input field. The file is removable, but its contents can also be cleared by using 'Delete private data' in Opera.
opera6.adrtext/plainNoStored bookmarks. The file can be saved and renamed, and another file can be selected from the context menu on the Bookmarks panel. Several third-party bookmark managers provide functionality to export to other formats.
opera6.initext/plainno [6]Stored program settings. If the file is removed, a new opera6.ini will be created by Opera on the next run, containing some basic settings. Use the command line switch /settings and add the file name/path to run Opera with a different settings file. See Opera6.ini Settings Explained and the System administrator's handbook for more information. This way you can make multiple shortcuts, which start Opera with different settings. (Use of the /settings parameter was broken in Opera 9.0-9.02.) Before reusing an opera6.ini file in another directory, first edit all the file paths to conform to the new location, to prevent Opera from storing user data in the old location.
oprand.datbinaryNoRandom seed file, used for generating keys
opssl6.datbinaryNoStored SSL preferences
override.initext/plainNoStored site specific preferences. Access from webpage context menu, and for all sites from Tools > Preferences > Advanced > Content. Can be hand-edited as well to allow more overrides than available in the dialog, but not all preferences can be set on a per-site basis.
override_downloaded.initext/plainYes, after performing a manual version check and once a week automaticallyAutomatically downloaded file with site specific preferences. User edits are kept unless they collide with items in the downloaded file.
search.initext/plainYesSettings for the search engines available in Opera, and where they are displayed in the browser. Only overwritten when the version number in the existing file is lower than that of the search.ini file in the main directory
spellcheck.initext/plainNoStored settings for the spelling check engine, like preferred language
urlfilter.initext/plainNoStored content blocking settings. The settings can be accessed from the webpage context menu, and for all sites from Tools > Preferences > Advanced > Content. The file can be hand-edited as well.
vlink4.datbinaryNoStored visited links. The file is removable, but its contents can also be cleared by using 'Delete private data' in Opera [5]
wand.datbinaryNoStored login data. The file is removable, but to clear all Wand data, you can also use 'Delete private data'. Single entries can be removed using the 'Server Manager' dialog
widgets.adrtext/plainNoStored settings for widgets, used to populate the Widgets menu and panel, to preserve the state of widgets (location/zoom) when widgets are closed and to determine how the widget should be uninstalled. When it is marked with 'clean uninstall', all widget data, including the widget package will be deleted when it is uninstalled.
bt_metadata
FilenameFormatOverwrittenDescription
*binaryNoStores BitTorrent metadata about which blocks have been downloaded and CRC checked, so Opera does not always need to recheck the whole torrent when you restart a stopped one.
cache4
FilenameFormatOverwrittenDescription
dcache4.urlbinaryNoIndex of the cached files. dcache4.url is updated on closing Opera. Cache settings can be found at Tools > Preferences > Advanced > History. The files are removable, but emptying the cache can also be done by using 'Delete private data' in Opera [5]
opr*.*same as the original filesNothe cached files
images
FilenameFormatOverwrittenDescription
*.*image/*NoIcon files, shown in bookmarks. Display settings are found in Tools > Preferences > Advanced > Browsing
keyboard
FilenameFormatOverwrittenDescription
standard_keyboard (1).initext/plainNoKeyboard shortcut setup file automatically created after editing keyboard shortcuts in Tools > Preferences > Advanced > Shortcuts. The file contains only the changed sections; missing sections will be taken from standard_keyboard.ini in the 'defaults' directory. Keyboard shortcut setup files can also be downloaded from the My Opera community
*.initext/plainNoDownloaded or manually copied and renamed keyboard shortcut setup files
menu
FilenameFormatOverwrittenDescription
standard_menu (1).initext/plainNoMenu setup file created after clicking 'Duplicate' in Tools > Preferences > Advanced > Toolbars. The file contains only the changed sections; missing sections will be taken from standard_menu.ini in the 'defaults' directory. Menu setup files can also be downloaded from the My Opera community
*.initext/plainNoDownloaded or manually copied and renamed menu setup files
mouse
FilenameFormatOverwrittenDescription
standard_mouse (1).initext/plainNoMouse gesture setup file automatically created after editing mouse gestures in Tools > Preferences > Advanced > Shortcuts. The file contains only the changed sections; missing sections will be taken from standard_mouse.ini in the 'defaults' directory. Mouse gesture setup files can also be downloaded from the My Opera community
*.initext/plainNoDownloaded or manually copied and renamed mouse gestures setup files
opcache
FilenameFormatOverwrittenDescription
dcache4.urlbinaryNoA special cache that will not be cleared, containing content received from trusted servers. By default only Opera's help files. The corresponding setting is NeverFlushTrustedServers in opera:config. (Opera 9.0x placed this directory under the main installation directory instead of under the Profile directory)
opr*.*Same as the original filesNo
sessions
FilenameFormatOverwrittenDescription
autosave.wintext/plainNoStored snapshot of the currently opened pages and windows in 'Saved windows' format. Used for startup option "Continue from last time", which is the default option on the recovery dialog after a browser crash.
*.wintext/plainNoManually saved sessions
skin
FilenameFormatOverwrittenDescription
*.zipzipNoDownloaded third-party skins. You can get more skins from the My Opera community
*.*image/*NoImages from the Web that you choose to use as Windows desktop background will be stored here. If you select an image more than once, multiple copies will be saved
styles
FilenameFormatOverwrittenDescription
user\*.csstext/cssNoA collection of user style sheets, copied over from styles when a profile is first created by Opera. Access them from View > Style; see Opera Style Sheets for descriptions. You can add you own user style sheets to this list by placing them in this directory. [4]
toolbar
FilenameFormatOverwrittenDescription
standard_toolbar (1).initext/plainNoToolbar setup file automatically created after changing the toolbar setup (hiding or showing of toolbars, panels; removing or adding buttons, and so on). The file contains only the changed sections; missing sections will be taken from standard_toolbar.ini in the 'defaults' directory. Toolbar setup files can also be downloaded from the My Opera community
*.initext/plainNoDownloaded or manually copied and renamed toolbar setup files
UnInst
FilenameFormatOverwrittenDescription
DfltBrws\32\*.*binaryNo, only on changing the default browser settingsFor each file type or protocol that gets associated with Opera, a file is saved containing the previous application that was associated with it. This way it is possible to restore the association to the previous owner. Changing associations can be done
  • from Tools > Preferences > Advanced > Programs > Details,
  • by changing the File associations from Windows Explorer,
  • by hacking the Windows registry (not recommended)
It is only possible to restore previous associations automatically when you use Opera's Preferences.
voice
FilenameFormatOverwrittenDescription
standard_voice (1).initext/plainNoVoice commands setup file automatically created after editing voice commands in Tools > Preferences > Advanced > Voice. The file contains the changed sections only; missing sections will be taken from standard_voice.ini in the 'defaults' directory
*.initext/plainNoDownloaded or manually copied and renamed voice setup files
widgets
FilenameFormatOverwrittenDescription
subdirectoriesvariousNoLocal storage for widgets, as cookies and cache are kept separate from Opera's normal cache
*.zipbinaryNoWidget files; can be downloaded and automatically installed from widgets.opera.com. Run and manage downloaded widgets from the Widgets menu. For debugging, you can also start an unzipped widget by dragging the config.xml to the browser.
widgets.dattext/xmlNoWidget data; associates the widget zip files with the local storage directories

Mail files

Main mail directory
FilenameFormatOverwrittenDescription
accounts.initext/plainNoStored settings for mail, newsgroups, chat, and newsfeed accounts. Not all items found in accounts.ini are active -- see also the Opera Mail Tutorial
imp.dattext/plainNoStored location of the last used import folder
incoming*.txttext/plainNoStored data on received messages for POP e-mail accounts, subscribed folders for IMAP accounts, used rooms and settings for IRC accounts, newsrc file for news accounts, and known feeds for the newsfeeds account
index.initext/plainNoData and settings for all items in the Mail panel
mailbase.datbinaryNoDatabase of received messages
*.newsrctext/plainNoList of newsgroups on server, and which postings have already been seen on subscribed groups
signature*.txttext/plainNoSignature for each account, will be inserted into messages in the compose window. Can be changed from the account properties in Opera Mail. Opera will automatically add the signature delimiter "-- " if it is not present in the signature itself
autofilter
FilenameFormatOverwrittenDescription
filter_8.initext/plainNoData for the learning filter of the Spam view; let the filter learn by adding and removing messages in Opera Mail. Editing these files is strongly discouraged
filter_*.initext/plainNoData for other filters set to 'learn' in the filter properties
indexer
FilenameFormatOverwrittenDescription
indexer*.datbinaryNoIndex data, determining which messages belong to which views
lexicon
FilenameFormatOverwrittenDescription
lexicon*.datbinaryNoLexicon of all words encountered in messages, to enable fast searching. Removing or hiding this directory will trigger a reindexing of all messages
store
FilenameFormatOverwrittenDescription
account*/*.mbstext/plainNoMailboxes organized by account and month, containing both in- and outgoing messages; Opera will automatically compress the mbs files when a certain percentage of the messages in it is deleted

Note 1

Separate language files (including a file containing the default English strings) can be downloaded from the download section of Opera's Web site. The file can be edited locally. Select the file from Tools > Preferences > General > Details. If you remove lines from the language file, the default English strings of Opera will be used for the missing strings.

Note 2

Variables from Opera6Def.ini are used in Opera to specify the correct paths to the policy and jar files, so the policy file itself does no longer have editable file paths that need to be edited on moving the main Opera directory after an install.

Note 3

The default setup files should not be modified; instead, use copies in the profile subdirectories.

Note 4

For tips and tricks regarding customization of Opera's style sheets, and to get help in making a nifty user style sheet, visit the newsgroup opera.customize.general, or the Customizing Opera forum.

Note 5

Editable with Joe Segur's Opera File Explorer, a third party helper application.

Note 6

On the first run old settings found in opera6.ini will be upgraded to new format where necessary.