Despite success in other browsers, Opera is the only major vendor not to support third-party add-ons. Fans passionately argue that Opera doesn’t need extensions because it offers more built-in functionality and configuration options than any of the competitors. Others claim Opera isn’t for them because it’s missing a essential feature.

The arguments should end with the release of Opera 11 — the first version of the browser to support extensions. Developers will be able to add or extend the browser’s functionality using standard HTML5, CSS, JavaScript and the supported APIs. Extensions will be based on the W3C Widget specification which may ultimately become an Open Standard.

Opera’s extensions will be similar to those offered by Chrome and Safari. That’s sensible — they’re easy to create and it should be relatively easy to port existing add-ons. In the first release, developers will be able to run background processes, add buttons, create menus, and manipulate interface controls such as tabs and the browser window. Opera is keeping it simple so they can focus on getting it right, but further API controls will be added as the system evolves.

Add-on installation will be a painless one-click and confirm process or you can drag an extension file into Opera. You probably won’t need to restart the browser.

The alpha release of Opera 11 will be available shortly. Extension development tutorials, guides and references will be published at

Will you consider using Opera once it has extensions? Could this feature raise Opera’s profile and its market share? Or is it too late?

Tags: extensions, opera
Craig is a freelance UK web consultant who built his first page for IE2.0 in 1995. Since that time he's been advocating standards, accessibility, and best-practice HTML5 techniques. He's written more than 1,000 articles for SitePoint and you can find him @craigbuckler

  • Akram Abbas

    Wow!!! I am an old user of Opera!!!! from when it was a shareware.. :P

  • Black Max

    As with all good things, the question isn’t an easy one. Opera is my browser of choice because it is sleek and fast, and extensions will slow it down (the reason why I don’t routinely use Firefox anymore — I’ve larded it down with extensions). On the other hand, I like some extensions and miss not having them for Opera. If they can work it so the extensions don’t slow Opera down, then woo hoo!

    • WinkyWolla

      If extensions will slow it down, why don’t you just not install any extensions? That way, nothing will change for you.

  • boen_robot

    Opera has supported Widgets since version… 9 I think (or was it 10.0?)… anyway, isn’t the W3C Widget specification supposed to be a formalization of THAT form of widgets? I understand the difference between an Opera widget and a Firefox/Chrome add-on (greather range of APIs for browser integration and interaction mainly), but apart from such (non-standard) UI APIs, I don’t think Opera has missed anything… or am I missing something?

    • Craig Buckler

      Widgets are slightly different — they’re more akin to Adobe Air than an add-on which extends or replaces default browser functionality. As far as I’m aware, Opera should be the first browser to support both … although you could argue that IE’s been doing that kind of thing for over a decade.

      • boen_robot

        I got that part, but it’s the part

        Extensions will be based on the W3C Widget specification

        that confuses me.

        I would think Widgets, as they stand in Opera (current and future versions), are (or will be) based on the W3C Widget specification, and extensions will be just as browser specific as all other browsers’ extensions.

      • WinkyWolla

        @boen_robot: Widgets and extensions can use the same packaging even if they have different purposes. Extensions will just use widget packaging.

  • Roshan

    looking forward to opera 11. its a pity that opera browser has been for so long without gaining considerable market, while Firefox and even Chrome have enjoyed their share of market success.

    • WinkyWolla

      Hmm, Opera has more than 140 million users, which translates to a global market share of 7%.

  • Black Max

    Opera will never enjoy a large share of the market, primarily because it’s not marketed so ferociously (and even if it was, it would have tremendous difficulty chipping away at Mozilla and Google’s market share). It’s a browser for tech-savvy users who care about standards and performance, and as such it will not crack the mass market in any discernible way. The folks at Opera, I imagine, have long since come to terms with reality and are simply making a great browser for those who prefer it. (As you can tell, I’m an Opera guy!)

  • samanime

    I’m actually a bit worried. I’ve noticed Firefox (and Thunderbird) getting more and more and more sluggish and bulky. I hope Opera isn’t about to go down the same path.

    • samanime

      Also, I have only manually added three add-ons to Firefox and one to Thunderbird. Others add in there own without me realizing and drag it down. I think with Opera supporting them, we’ll start seeing installs that secretly install their own Opera extensions too.

      • Black Max

        Ugh, let’s hope the Opera folks don’t let that happen.

    • Craig Buckler

      I wouldn’t worry too much. Like Chrome, Opera’s extensions are little more than bookmarklets with a sprinkling of API calls. Firefox offers far deeper add-on customisation — process-intensive or badly written extensions can slow down the browser.

      • James Edwards

        You couldn’t be more wrong :P

        Chrome extensions are, as you say, little more than bookmarklets with an icon.

        But Opera extensions are far more than that — they can insert scripts and stylesheets into the current page (using the same domain opt-in mechanism as userscripts), they can also create custom dialogs (a bit like chromeless windows), and they run a global background process which can do things like cross-domain Ajax, global localStorage (ie. preferences that persist across all domains, or are domain-specific), and provides full access to the windows and tabs heirarchy. There’s also a communication mechanism that runs between each of the components, so they can send each other messages using the HTML5 cross-document communication framework.

        So while it’s true that Opera’s extensions API is nowhere near the sophistication of Firefox’s XUL, it is however significantly more sophisticated and capable than what Chrome offers. And this is only the first release :)

      • Craig Buckler

        Thanks James. That didn’t come across in their press release…?

        Even so, I don’t think there’s too much reason to worry. It still amazes me that people complain about Firefox when they have 157 conflicting extensions installed.

      • James Edwards

        Yeah Opera have a habit of understating their products’ capabilities. There’s something very British about that — especially for a Norwegian company!

        Opera are in a unique position, being the last of the major browsers to introduce extensions, to learn from the mistakes of others. I don’t think anybody would like to see another browser implement something as complex as XUL. But Chrome’s offering doesn’t have enough stuff to be interesting. [And IE8’s Webslices and Accelerators are just silly!]

        Opera seem to have struck a good balance so far. But it’s the 2nd and 3rd iterations of the API I’ll really be looking forward to :)

  • skunkbad

    I’d consider using Opera if it came out with a web developer’s toolbar that was better than the one I use with Firefox. I must have that toolbar.

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