Browser behavior


By default, Opera caches all content (documents, images, and other content) on webpages. To enable rapid access, Opera uses your computer’s memory to store recently visited webpages. It’s generally a good idea to let Opera handle memory caching automatically.

To display the cache, type opera:cache into the address field.

Cache options

Opera stores visited pages both in memory and on disk, so they will be available after a restart. To change the cache settings, go to Preferences > Advanced > History and choose from the following options in the Disk Cache section:

Action How to do it Notes
Empty the cache Click Empty now This deletes all cached content from the disk
Change cache disk size Choose the size from the drop-down list Increase this if you want to keep more local copies of pages, and for longer. Zero means that writing to disk will be avoided as far as possible.
Empty cache on exit Check Empty on exit. This deletes the cache automatically every time you exit Opera
Change how often cached pages are checked for updates In the Check if cached page is updated on the serversection, select a less-frequent time interval from the drop-down list for either documents or images The browser checks for new versions when you revisit a page, even though most web content is not updated very often. Checking for changes less often may speed up browsing. Note that you may sometimes have to reload to get the newest version.


Cookies are small data files that store information in connection with a website. For example, a cookie may be created to store the contents of an online shopping basket, or to confirm that you are logged in as you browse the pages of a site. When a cookie is set, the sequence of events is the following:

  1. During first contact, the website offers you a cookie for a specific domain. If you accept the cookie, it is saved on your computer.
  2. Every time you make contact with a resource in that domain, the browser sends the cookie.

There is a reason for this rather abstract formulation: the cookie need not originate from the website whose address is given in the address field of the browser. For example, the website you are visiting may contain an advertisement in the form of an external image, and the site delivering the external image may offer you a cookie. These so-called third-party cookies are frequently used for marketing purposes.

Cookies can be used to construct a profile of your browsing habits, and are therefore regarded by some as a privacy issue.

If no expiration date is assigned to it, a cookie expires at the end of the session, when you exit the browser. A cookie that expires at end of session is called a session cookie.

Cookie preferences

Preferences > Advanced > Cookies

The cookie preferences give you control of Opera’s cookie handling. The default setting is to accept all cookies.

Accept cookies
All cookies are accepted (default)
Accept cookies only from the site I visit
Third-party cookies, for a domain outside the one you are visiting, are refused
Never accept cookies
All cookies are refused

Delete new cookies when exiting Opera

Some websites require you to accept cookies to use their services. If you want these sites to work, but you do not want to keep cookies between visits, select “Delete new cookies when exiting Opera”.

Ask me before accepting cookies

If you select “Ask me before accepting cookies”, the cookie dialog opens every time a cookie is offered, with information about the cookie’s origin and attributes.

Manage Cookies

The cookie manager permits you to inspect and edit the cookies saved by Opera. Press the button marked “Manage Cookies” to reveal a set of folders, each identified with a domain. Use the quick find field to search by domain name, and open the relevant folder to get detailed information about all cookies connected with that domain.

The cookie dialog

The cookie dialog opens every time a website offers you a cookie, if you have checked the box marked “Ask me before accepting cookies” in Preferences > Advanced > Cookies. The dialog describes the cookie’s origin and attributes, and gives you the opportunity to accept or reject it.

Force deletion when exiting Opera

To change the expiration of the cookie to end of session, select “Force deletion when exiting Opera”.

Remember my choice for all cookies for this domain

If you want to accept or reject all cookies with the same domain, select “Remember my choice for all cookies for this domain”. The next time a cookie is offered for this domain, the cookie dialog will not appear.

Cookie details

Cookie attributes are available under the heading “Cookie Details”.

Do not ask me about cookies again

If you prefer not to see the cookie dialog, select “Do not ask me about cookies again”. Checking this box is equivalent to unchecking the box marked “Ask me before accepting cookies” in the cookie preferences.

Site-specific cookie preferences

Site-specific cookie preferences may be set by Ctrl-clicking the page you are visiting, selecting “Edit Site Preferences” from the menu, and activating the cookie tab. The options are the same as described above for the general cookie preferences.


Opera will display a notification message when:

  • New email, feed, or news items arrive
  • Pop-ups are blocked
  • Downloads are completed
  • Opera Unite applications are updated

To disable some or all of these notifications, go to Preferences > Advanced > Notifications.

With OS X Mountain Lion, you can receive Opera notifications, for example mail or Opera Turbo notifications, in the OS X Notification Center.

Note: No notifications will be displayed when you are using another application, such as a multimedia player, in full-screen mode.

Page icons

A webpage can specify a small icon to represent itself. Opera will display this icon on tabs and bookmarks.

The standard method of doing this is to specify link rel=”shortcut icon” in the page document. However, on some servers a file called favicon.ico is put in the root directory without a link from the document.

By default, Opera will display both types of icons.

Page icon settings

If you want to ignore all webpage icons, or to display only icons correctly linked from within documents, you can change the settings. Go to Preferences > Advanced > Browsing and choose the required settings in the “Page icon” field.

Page loading

Page loading is how long a webpage takes to fully display all text, images and so on. This is sometimes referred to as “drawing”. You can set your preference for how soon Opera should attempt to display a page after it starts loading.

To change page loading settings, go to Preferences > Advanced > Browsing under “Loading”.


Many multimedia files on the web require third-party software, known as plug-ins, to be played. A common example is a media player to play videos or music. When Opera detects the need for a plug-in that is not installed, it offers to take you to a site to download it, or offers to download it for you.

Turn plug-ins on or off

If you want to disable plug-ins completely, go to Opera/Settings > Quick Preferences and uncheck “Enable Plug-Ins”. Then you will only see files that Opera can display by itself. Check this option to enable them again.

Alternate menu path: Preferences > Advanced > Content.

Set specific site preferences

If you want to disable or enable plug-ins for a particular website, you can use site preferences.

Report a plug-in crash

When a plug-in crashes, a bar displays at the top of the window, offering the following options:

  • “Report This Issue” allows you to report the crash to us so that we can investigate and seek solutions.
  • “Reload Page” attempts to restart the plug-in so that you can view the webpage.
  • “Done X” leaves the crash and does not attempt to restart the plug-in. You will not be able to view affected elements in the page.


Opera’s preference dialog holds a great number of useful settings to change the browser behavior to suit you.

Access the preferences by going to Opera/Settings > Preferences or by pressing ⌘+, or Ctrl + F12.

Preferences tabs

The Preferences dialog has 5 tabs (note that the Advanced tab is split into distinct sub-topics):

Tab Allows you to change settings for …
Advanced: Tabs topic
Advanced: Browsing topic
Advanced: Notifications topic
Advanced: Content topic
Advanced: Fonts topic
Advanced: Downloads topic
Advanced: Programs topic
Advanced: History topic
Advanced: Cookies topic
Advanced: Security topic
Advanced: Network topic
Advanced: Storage topic
Advanced: Toolbars topic
Advanced: Shortcuts topic

Use other programs for certain actions

Preferences > Advanced > Programs

Choose which programs Opera should use to handle specific protocols.

Protocol manager

You can create your own list of programs to launch when executing particular protocols in Opera. The default list includes:

Protocol Purpose
mailto Choose which application Opera should use for email; Opera’s own built-in client, the default email client on your computer, or a specific other email client.


Scroll bar

The scroll bar is used to view long webpages and allows you to move up and down the page. This is normally placed on the right side of the screen, indicating the length of the current document and your current position within it. If you encounter a webpage wider than your screen, you will see a scroll bar along the bottom of the window to allow you to move across the page.

Scroll a document by clicking on the arrows at either end of the scroll bar, or by dragging the indicator with your mouse.

Turn scroll bars on or off

If you prefer not to see the scroll bars, you can uncheck this option. Go to Preferences > Advanced > Browsing and select or deselect “Show scroll bars”.


These are small, useful boxes that display to provide you with relevant extra information when you hover certain parts of the Opera browser or webpages with your mouse. For example, when you hover the buttons on the address bar, a small box displays under your mouse cursor that tells you what that button is, and may provide any relevant keyboard shortcuts you can use instead.

Turn off or on

To change this setting, go to Preferences > Advanced > Browsing and either uncheck “Show tooltips” if you do not want to see them, or check it to display them.