Developer tools

Developer tools are used for developing and debugging local and remote web pages. These include a DOM view of web pages and a highlighting of elements. You can step through your JavaScript code, quickly inspect changes to your CSS styles, debug your creations, and study your application’s impact on network resources. Developer tools allow remote debugging, making it possible to debug web pages as seen on a mobile phone or a television from your desktop.

The complete list of developer tools is too long to detail here. For more information, please review the developer tools user guide.

For Mac users, to open developer tools, select View Show Developer Menu. A new submenu called Developer will appear on the menu bar. To use the tools, select Developer > Developer Tools.

For Windows and Linux users, to open developer tools, go to O MenuDeveloperDeveloper Tools.

To close developer tools, click the X button in the upper-right corner of the developer tools window.

Proxy settings

A proxy server is a computer that can, for example: store local copies of pages for quick access, act as an interpreter between your browser and a special service, alter or monitor information exchange, or speed up web communication.

To change your proxy server settings:

  1. Go to Settings.
  2. Click Advanced in the left sidebar, and click Browser.
  3. Under System, click Open your computer’s proxy settings.

All traffic using the respective protocol will go through the proxy server you specify. To use a proxy, you need to specify:

  • A protocol, such as HTTP
  • A web address, such as or
  • A port number, such as 5000

You can get this information from your internet service provider (ISP), the host of your proxy server, or the documentation that comes with your proxy software.

You can specify whether you want the proxy used for even local servers by checking the Use proxy for local servers checkbox.

If your internet provider requires automatic proxy, please enter the web address provided by your ISP.


Opera allows you to test out experimental features, new capabilities, and alternative configurations for your browser. You can read about and enable experiments by navigating to opera:flags. Opera experiments are unstable and are not recommended for casual users. Enabling experimental features can compromise security and privacy and may delete data. If you choose to enable experimental features, you should proceed with caution on a properly backed-up computer.

Playing premium media content on ARM on Mac devices

If you are using a newer Mac device, you may experience an error when attempting to play premium videos or music, or you may get a message asking you to install additional software called Rosetta.
You will see a pop-up prompt that allows you to launch the Rosetta installer directly. You can take action by clicking “Install Rosetta.”

  1. On your Mac, open Finder > Go > Go to Folder
  2. In the Go to folder input box, type: /System/Library/CoreServices
  3. In the resulting files, double-click the Rosetta 2 Installer
  4. Follow the instructions provided to complete the installation
  5. Restart Opera

What is Rosetta?
Rosetta is an application provided by Apple to improve compatibility with some of their new Mac devices. You can learn more about Rosetta on Apple’s developer website.