NotScripts Brings Firefox NoScript Protection To Opera

Martin Brinkmann
Nov 14, 2011
Updated • Jul 23, 2016

When it comes to add-ons, the NoScript add-on for the Firefox web browser is my favorite one. It blocks script from running on domains until I allow them to run. NoScript offers more functionality than that like XSS protection and other security-related features that make it the best security add-on there is.

I have reviewed the Google Chrome extension NotScript in the past which offers a somewhat limited NoScript experience for that browser. And Swapnil (thanks) just informed me that Opera too has a NotScript extension available.

NotScripts is available for Opera 11.10 up to Opera 12.x but not the recent Chromium version of the browser.

Update: NotScripts and NotScripts Suite Lite are available for the new Opera web browser. The instructions below are for the classic Opera browser up to version 12.x.

NotScripts for Opera


The installation process is a bit on the complicated side. Here are the instructions on how to install NotScripts correctly.

  • Install the extension. You can install the latest NotScripts version right from the Opera Extensions repository.
  • Close the Opera window and re-open Opera.
  • Click the NotScripts button in the Opera toolbar.
    It would show you a message saying you to set User JS Storage Quota to 5000. Click the message and it will take you to the 'User JS Storage Quota' setting.
  • Change the value of the setting from 0 to 5000.
  • Click the Save button. You might need to scroll down to find the Save button.
  • You may need to restart the Opera browser before the changes take effect.

NotScript Modes and Usage

Opera's Notscript, unlike NoScript comes with three different script blocking modes. The default mode is whitelist which blocks all scripts except those that are run from whitelisted domains.

Blacklist, the second mode allows all scripts by default and blocks only scripts on a user maintained blacklist (much like the Firefox add-on YesScript).

The last mode Whitelist + Same Origin uses the whitelist approach to block all scripts but allows scripts running on the domain that is loaded in the browser. So, if you would open scripts that originate from the site would be allowed but scripts from any other site would not be.

So more choice in this regard which is really nice. When you visit a site you need to click on the NotScript icon to display the list of blocked scripts. There is no indicator that scripts are blocked which is probably the biggest usability issue. A click on the icon displays the scripts with options to allow, block or temporarily allow them individually.

If you run blacklist mode (allow all scripts except selected ones) then you see a script listing similar to that on the screenshot above. The blue action is the current one for a script on that particular site. Just like with NoScript, you can allow all scripts, globally allow all temporarily until revoked, or temporarily allow the shown scripts.

NotScript seems to work considerably well. I have two big gripes with it. First the missing notification as it is a guess game if a script has been blocked or not, and second that the developer has not updated the script in a while (the last update dates back to April 2011).

The extension itself works and that's the most important aspect obviously. It is not a 100% port of NoScript but a port that brings the most important feature of the Firefox security extension to Opera. For that, it is highly recommended to be installed.

An alternative to that is the Opera NoScript Alternative BlockIt which I have reviewed in the linked article. It is also only available for classic Opera.

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  1. Giorgo said on April 5, 2014 at 6:41 pm

    @”NotScripts is available for Opera 11.10 or newer…” – WELL, THAT IS DEFINITELY NOT TRUE!



    1. Martin Brinkmann said on April 5, 2014 at 7:01 pm

      I modify the article. When it was written, Opera had not made the switch to Chromium yet.

  2. Thrawn said on November 23, 2011 at 7:25 am

    Actually, Firefox’s NoScript does support the three security modes mentioned in this article; they’re just not always called that.

    Default behavior is the same (block unless whitelisted).
    Selecting ‘Allow Scripts Globally’ (context menu or status bar) gives you the default-allow mode with blacklisting.
    Selecting ‘Temporarily allow top-level sites by default’ (options dialog) allows scripts from the same domain as the page.

    It’s good that Chrome and Opera have this, but I still opt for the full version; NoScript goes beyond just JavaScript.

  3. Nicolai said on November 14, 2011 at 8:09 pm

    Well, NoScript is still #1 for all-around protection. NoScript does a lot of things; Block Scripts, Anti-XXS, ClearClick, Forbid plugins / WebGL / font-face / etc, ABE, Force HTTPS ( + Cookies), etc, etc, etc
    And it does the job well (unlike others)!

    1. Martin Brinkmann said on November 14, 2011 at 8:42 pm

      I agree :)

  4. Swapnil said on November 14, 2011 at 6:07 pm
    1. Martin Brinkmann said on November 14, 2011 at 6:59 pm

      While it does offer the core feature of NoScript, it fails to implement the other security features of the extension. But it is definitely a great add-on.

  5. Swapnil said on November 14, 2011 at 6:04 pm

    “And Swapnil (thanks) just informed me that Opera too has a NotScript extension available.”

    You should not thank me – I am very thankful to you for writing about this extension. Once again, thankyou very very much.

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