Opera Software
  1. Toolbars
  2. Menus
  3. Panels
  4. Speed Dial
  6. Opera Widgets
  7. Notes
  8. Geolocation
  9. Opera Link
  10. Opera Turbo
  11. Opera Unite
  12. Content blocking
  13. Fraud and Malware Protection
  14. BitTorrent
  15. Display modes
  16. Developer tools
  17. Preferences
  18. Advanced Preferences
  19. Skins
  20. Keyboard shortcuts
  21. Using the mouse
  22. E-mail and news
  23. Feeds
  24. Chat
  25. Dialogs
  26. Auto-update
  27. Backing up Opera

Developer tools

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Opera includes several tools to aid web developers, most importantly Opera Dragonfly, a tool that enables remote debugging of webpages.

The developer console is a tool for analyzing and/or interactively modifying a webpage during development or debugging, while the source viewer is a simpler tool for examining the source code of a webpage, and making quick changes.

Opera Dragonfly

Note: to use Opera Dragonfly, JavaScript must be enabled.

Opera Dragonfly is a JavaScript application used to debug local and remote webpages. To open it, select the menu item Page > Developer tools > Opera Dragonfly. The user interface contains seven tabs:

Opera Dragonfly is still in development. For more information, see the following articles:

The developer console

Like the other JavaScript applications on Dev.Opera, the developer console can be dragged and dropped onto any Opera toolbar. When you open the developer console, a small window will appear on top of the webpage to be analyzed, with five tabs: DOM, JS, CSS, HTTP, and About.

Note: to use the JavaScript applications on Dev.Opera, pop-ups must be enabled.

The developer console opens in the DOM tab, with the list of nodes collapsed under "document". Click on the plus sign to expand the list. When you click on a node, the webpage will flash briefly to indicate the region associated with this node.

Alternatively, clicking anywhere on the webpage will open up a list of DOM nodes, with the node relevant to that region of the page highlighted. To find the relevant region, press and hold the Shift key while scanning the page with the mouse.

The following are key features of the DOM tab:

The developer console can be used to interactively modify a webpage. The "Remove" button in the DOM tab permits removal of nodes, but also any CSS property can be edited from within the CSS tab, after pressing the button "Show rules" for the appropriate style sheet. The result of the changes is displayed instantly, and can be exported for later use.

A more detailed discussion of the developer console can be found on Dev.Opera.

The source viewer

Opera includes a simpler tool for analyzing and modifying webpages, the source viewer. If you want to have a look at the source code of the current webpage, go to Page > Developer Tools > Source, or press Ctrl+F3, or right-click the page and select "Source".

The source viewer opens in a new tab on your tab bar, and has syntax highlighting to give you a better overview of the source. If you want to edit the page, you have two options:

  1. Save to cache and see your changes applied immediately by clicking "Apply changes", or pressing Ctrl+R.
  2. Save to a location of your choice by clicking "Save", or pressing Ctrl+S.

Note that if you are editing a locally saved document "Apply changes" will permanently save your changes.

If you prefer to use an external program for source viewing and editing, you can specify this in the programs preferences.