Security and Privacy in Opera

Referrals, redirections, and cookies

Referrals and redirections

The settings in Settings > Preferences > Advanced > Network determine how Web servers handle and monitor your Internet activities, as described below.

Send referrer information
Some Web sites register the site that referred you to them. This information can be used to tailor content based on the site that you came from. If you prefer not to allow a Web site to know where you were before visiting it, especially if you were on a local, secure, or restricted site, uncheck this option to disable it. Note, however, that some sites depend on referrer logging internally.
Enable automatic redirection
Sometimes a site might redirect your browser to a different URL, often because the site has moved. Leaving this option enabled does not constitute a big security risk, but turn it off if you want complete control of what sites you visit.

Cookies

Cookies are pieces of information stored in files that Web servers store on your computer when you are browsing. These pieces of information allow servers to recognize your computer the next time you visit their sites. Cookies are not viruses and cannot cause direct damage to your computer system in any way, but they may record your browsing habits in intrusive manners and trace your movements across different Web sites.

Some sites use cookies to store your username, for example, so that you do not have to retype your password when you check your e-mail for a number hours after you log in. This is convenient, but it can also be a security hazard if others have access to the computer you are using.

Delete cookies

To ensure that cookie information is kept in the browser, select Settings > Preferences > Advanced > Cookies and check "Delete new cookies when exiting Opera" and close Opera when you have finished browsing.

Enable or disable cookies

You may also decide that you want to disable cookies. Note, however, that you may have difficulties logging on to a significant amount of Web sites if you disable cookies. To disable cookes, select Settings > Quick Preferences and uncheck "Enable Cookies".

Invalid cookies

There are types of cookies that Opera will refuse regardless of whether you have set the browser up to handle all cookies. These are cookies set for top-level domains: domains ending in .com, .net, and .org, among others. Such cookies are considered invalid or illegal and are blocked because:

Configuring cookie settings

You can chose to allow all cookies to be stored on your computer, refuse all, or selectively allow certain cookies and certain types of cookies. To manage your cookie settings, select Settings > Preferences > Advanced > Cookies and select from the following options:

Accept
Accepts all cookies from all sites
Accept only from the sites I visit
Allows only cookies that are set by the Web site you are visiting, not by any other sites whose content is displayed in frames or via images on the current page
Never accept cookies
Does not accept any cookies from any site
Prompts you to accept or deny every time you receive a cookie
Manage cookies
Displays your Server Manager, which lists all the domains you currently have cookies from. You can add new domains, delete the domains you do not wish to keep cookies from, and edit cookie settings specifically for each server.

You can also change cookie settings for a specific site, using site preferences. Select Settings > Quick preferences > Edit site preferences.